Subtracting Rational Numbers*

Transcription

1 Subtracting Rational Numbers* Name ; i. To subtract a rational number, add its opposite = _J_ = +10 Subtract. 1. +s.1 - +e.e =. -s.1 - -s.1 = s.01 = = ;7.1 = = = s - +.s = a - -2.a = 12. +g.s = 1. +s _ = 1. -_g_ - -5_1_ = _ +2- = l_ - -5_1_ = _ - + = _g_ _ = Simplify each expression. Use the rules for order of operations (O - +s.6) = cs.7 - -o.) = s.os - (-s.1 - -s.1) 2. ( o. 7) = c o.0) - ( ) 27. Mrs. Moffet's special account has a balance of $.06. She writes a check for $50. What is her new balance? 28. A chemist takes a liquid at C and cools it until its temperature is C. Find the change in temperature. *Use with Lesson -, text pages Copyright Sadlier-Oxford 1

2 Multiplying Rational Number.s* 1 Name N_ faaj /'K The product of two rational numbers with different signs is negative; with the same sign is positive.,,, Find the product x +2 = x +2 =. + x +12 =. -1 x - = 5. -a x -2 = x -5 = 7. - x -7 = 8. -a x + = 9. + x - = 10. +s x +g = x +2 = x -5 = x -g = 1. -a x - = x -g = x -o. = 17. -o.os x -o. = 18. +s.1 x -7 = 19. +s.1 x -2 = 20. -_ x = x = s. 78 x +2.6 = 2. x 2 = 2. x 6 =! l x = x 9 = x 9 6 = _!_ _!_ + 1 x 5 8 = x = x = Compute. Evaluate. 7. 6y when y = t when t = som when m = whens = O *Use with Lesson -6, text pages Copyright Sadlier-Oxford

3 Dividing Rational Numbers* N~1/~ Name The quotient of two rational numbers with the same sign is positive; with different signs is negative. Complete x ---- = x = = = -8. -g x -7 = x = = rn x = x -g = = -18 Divide g = = ~ = - = = 12. ~ = = = +g = Find the quotient rn -g = -5 = = 20. -_5 +o.7 = = _?_ = = 2. +5_?_ 5 +7_2_ 15 = _?_ = }_ = _E_ 9 = 0. (-28 x +20) -8 = *Use with Lesson -7, text pages Copyright Sadlier-Oxford

4 Solving Equations* (Multiplication and Division) Name Write an equation for each. Then solve it. 1. Four times a number is negative A number divided by negative is positive 7.. A number times negative 9 is negative 6.. Seven times a number is negative : r ' fl 5. 7x = +g 7. 9r = +s1 x = a=---- r = s 9. -at = +o y = o.12a = +1 t = ---- x = ---- y = a= c = c = d = 5 d = b = r = b = r = : t = -00 t = 18. 1n = +g1 n 19. 8x = -6 f = +16 x = f = 21 a -a. +g = a = b = +1 b = d = 5 c = ---- d = ---- e 25. -=f = e = 26. -~ = -_ 7 h = 27 a -a -o.7 = 28 n -6 _1._. +10 = 5 a=---- n = ---- t = +26 t = 0. _c = -10 ~ c = n 1. + = +6 x 2. _ 2 = +s.s n = ---- x = ---- *Use with Lesson -8, text pages Copyright Sadlier-Oxford 5

5 Name Find the LCM for each equation, when needed. Then solve s + 2x = -1.s 2. 2k - 6 = x = 8.S. ; - s = 1S 5. -fa- + = s'1- + 1S = 17 s 7. 1S = 1S n + = 8.S 9. y - 11 = 2S 10. y - - = -2s 11..6y +.2 = 1S s = -10 Combine like terms. Then solve. 1. c Sc = a a = -o Sr + 2r - 1 = -6 l ' x x = sy y = +sf 18. 9d d = 6 ' x x = c - 20c = t - 19t = 21 Solve equations, using grouping symbols if needed x x = n + = = a 25. 5x - x - =.2 use with Lesson - 9, text pages Copyright Sadlier-Oxford

6 t Ratios and Rates* Name V_~_ 1 /'8 _ Write a ratio. Express it as a fraction in lowest terms. Change to like units where necessary out of 1 O people use Sure Glue. girls in a class of 9 students 5. 8 apples in a basket of 2 dozen out of every dollar goes to entertainment. The number of even digits to the number of odd digits in 9,21, inches out of a yard Write as a rate in simplest form. 7. pages in 5 hours 9. $50 a month shirts for $ yards in 0 seconds 8. 7 books in 8 weeks cans for $ guppies for $ bags for $. 50 Write an equal ratio in lowest terms : : : : : : : : :8 2. 2: :2 1 5 _g. ~ 27. 1: _g. ~ : : : : : : : Justin is 7 years old and his granddad is 77. What is the ratio of Justin's age to his granddad's age? 7. What is the ratio of the number of vowels to the number of consonants in this question? 56 *Use with Lesson 6-1, text pages Copyright Sadlier-Oxford

7 t Proportions* Name N_ h-'_ 1 /~ _ Write= or~ : 18 : : 60 : :90 5 : :27 : _:1_ _g_ n x 6 = a n = x = ---- a= b a r b = ---- a=---- r= s 20. b c 1. 1 s = ---- b = ---- c = a o.~ = ~:~~ a=---- n = ---- t = r 2_:1_ b s 2 1 = r= ---- b = ---- s = o.~5 = ~:~ 0..6 c c = a=---- c = f 2. 5 cm on a map represents 1 0 kilometers, how many kilometers will be represented by. 8 cm? *Use with Lesson 6-2, text pages Copyright Sadlier-Oxford 57

8 Finding a Part or a Percentage* Name fv#vj 1(f Find the part or percentage of each number % of 0 = 2. 75% of % of 2. 0% of 90 = 5. 5 /o of 70 = 6. 20% of 100 = 7. 80% of 10 = 8. 2% of % of 78 = 10. 2% of 28 = 11. 1%of % of 20 = 1. 12f% of 56 = 1. ~ % of 8 = ; % of 26 = % of ~ % of 2 = ; % of 5 = 19. : % of 620 = % of /o of 0 = 22. n order to determine the need for traffic signals at a suburban intersection, a 8-hour watch was kept. During that time, 12 ~ % of the 82 cars recorded made left-hand turns. How many cars was this? 2. During the same watch, it was noted that 16 ~ % of the cars made right-hand turns. How many cars made right-hand turns? 2. Last summer, Julie earned $15. This summer, she earned 25% more. How much did she earn this summer? 25. 0% of 50 students play a musical instrument. How many students play musical instruments? *Use with Lesson 7-, text pages Copyright Sadlier-Oxford 65

9 ch: Finding Percent* Name LY_~_ 1 J'8 _ Find the percent. Round to the nearest tenth, if necessary. 1. What percent of 8 is 2? 2. What percent of 9 is?. What percent of 25 is 5?. 8 is what percent of 0? is what percent of 50? 6. What percent of 16 is 8? 7. What percent of 120 is 80? 8. What percent of 9 is 72? is what percent of 99? 10. What percent of 8 is 6? 11. What percent of 1 is 9? is what percent of 90? 1. What percent of 2 is 2? _ 1. What percent of 500 is 600? iswhatpercentof6? 16. What percent of 96 is 62? 17. What percent of 55 is 182? 18. What percent of 22 is 10? _ 19. A team won 18 games and lost 9 games. The number of games won is what percent of the total games played? 20. Bob earned $810 last summer. He spent $50. What percent of his earnings did he save?' 66 use with Lesson 7-, text pages Copyright Sadlier-Oxford

10 Finding the Original Number* Name Find the original number. 75% of n = 27 75% x n = 27 n = 27 75% n = 6 1. % of a = % of b = 9. 50% of c = 16 a = b =. 20% of d = % of e = c = 25% off = 20 d = e = 7. 75% of g = % of h = g = h = 10. 5% of j = 20..l_ %ofk = j = k = ~%of m = 1. 12f % of n f = ~%of i = 17 i = 2% of = 8. = 2.5% of o = 12 _!_ 2 m = n = 0 = % of p = % of q = % of r = 12 p = q = r = Complete the table. a = rate; b = percentage; c = original number or base a b c 19. 1% % % ; % % ; % 6 *Use with Lesson 7-5, text pages Copyright Sadlier-Oxford 67