Record and Practice Journal Answer Key

1 Record and Practice Journal Answer Key Big Ideas Math Green Copyright Big Ideas Learning, LLC answers All rights reserved. 2811. ()()()2, 2 , 4, 4 , and 4, 2 Chapter 7 Fair Game Review 1. 30 2. 10 3. 17 4. 6 5. 6 6. 44 7. 16 8. 72 9. 85 10. 23k+ 11. 82q+ 12. 6p 13. 9x 14. 5n 15. 13y+ 16. 2c 17. 62p+ Activity 1. What is the area of a rectangle that is 5 feet long and 2 feet wide?; 210 ft 2. a. Sample Answer : At a supermarket, every fifth customer will receive a $10 coupon and every seventh customer will receive a $3 coupon. How many of each type of coupon are needed if there are 400 customers? 80 $10 coupons; 57 $3 coupons b. Sample Answer : Is 445 feet 10 inches about one and a half times the length of a football field? yes c. Sample Answer : A taxi charges $ for the first mile and $ for each additional mile. You travel 13 miles. You give the driver $20. How much change do you receive?

2 $ 3. Rewriting a word problem by leaving out information you do not need to solve the problem makes the problem easier to read and easier to solve. Answer should include, but is not limited to: Students will write a word problem with more than 50 words. They will rewrite the problem using at most 25 words and include only the information needed to solve the problem. Practice 1. 273y= 2. 43x = 3. 817p+= 4. 142q= 5. 2832x+= 6. 320x= 7. 5616x+= Activity 1. a. Sample Answer : A sphere represents the variable n. A cube represents 1. The three cubes on the left side represent 3 and the seven cubes on the right side represent 7. One sphere weighs the same as 4 cubes. If you take away the 3 cubes on the left side of the scale, you have to take away 3 cubes on the right side of the scale. The scale will still be balanced with 4 cubes on the right side. So, b. Sample Answer : Substitute 4 for n to get 43 7, or 7 7.+== So, the solution checks.

3 C. Sample Answer : model on the left; The model on the left represents When you substitute 8 for n, you get 81 9,+= or So, it checks. 2. a. 5 b. 9 c. 3 d. 0 3. 4. Sample Answer : The equations in parts (d) and (e) are subtraction equations instead of addition equations. So, if modeling, you need to use addition to get the variable by itself instead of subtraction as in the other equations. xy3421 4 2 34321O 2 3 4( 2, 2)(4, 2)(2, 2)(4, 4)( 4, 4)( 4, 2)Equation Question 15x+= What number plus 1 equals 5? 411m+= 4 plus what number equals 11? 83a=+ 8 equals what number plus 3? 921x = What number minus 9 equals 21? 134p= 13 equals what number minus 4? Equation Solution Check 15x+= 4x= 41 5+= 411m+= 7m= 47 11+= 83a=+ 5a= 853=+ 921x = 30x= 30921 = 134p= 17p= 13174= Record and Practice Journal Answer Key Copyright Big Ideas Learning, LLC Big Ideas Math Green All rights reserved.

4 answers 29 5. a. true b. true c. false; It can be on either side. d. false; If you add to one side, you should add to the other side. 6. If an equation involves addition, subtract the same number from each side to solve the equation. If an equation involves subtraction, add the same number to each side to solve the equation. Sample Answer : 13 13 11 +1 +124xxxx+= = == 7. yes; Sample Answer : The first equation states that 5x is equal to 12. The second equation says that 12 is equal to Even though the equations are stating the equality in a different order, the equations are making the same statement. So, they are equivalent. Practice 1. yes 2. no 3. yes 4. yes 5. 4k= 6. 37p= 7. 23b= 8. 1330m= 9. 15190175ww+== Activity 1. Check student s work. Student can use mental math or guess, check, revise to find the missing dimension. a. 4x= b. 4x= c. 7x= 2. a. 312;x= Sample Answer : One sphere weighs the same as 4 cubes.

5 Because you divide the left side of the scale by 3, you have to divide the right side of the scale by 3. The scale will still be balanced with 4 cubes on the right side. So, each person pays $4. b. Sample Answer : Substitute 4 for x to get ()3 412, or So, the solution checks. 3. a. each robot s share; ;x= each robot s share; Divide each side of the equation by 3; $ b. robot s weight on the moon; 696;x= robot s weight on the moon; Divide each side of the equation by 6; 16 lb c. number of feet robot runs in 1 minute; 6;60x= number of feet robot runs in 1 minute; Multiply each side of the equation by 60; 360 ft d. height of each robot; 414;x= height of each robot; Divide each side of the equation by 4; ft 4. The inverse operation of addition is subtraction. The inverse operation of subtraction is addition. The inverse operation of multiplication is division. The inverse operation of division is multiplication.

6 5. To solve an equation involving multiplication, divide each side of the equation by the same number. To solve an equation involving division, multiply each side of the equation by the same number. Sample Answer : 3939333xxx=== 26626612xxx= = = Practice 1. 11k= 2. 50p= 3. 36m= 4. 9a= 5. 6. 7. 58517aa== 8. 307210tt== Activity 1. a. b. Sample Answer : hours worked, h; money earned, A; The ordered pairs (h, A) represent the values in the table (hours worked, money earned); The horizontal distances are the same as the pattern between the values in the left column of the table. The vertical distances are the same as the pattern between the values in the right column of the table. Hours worked Money earned (dollars) 1 8 2 16 3 24 4 32 5 40 1823451624324000+1+1+1+1+1+8+8+8+8+8 Hours workedMoney earned (dollars)Ah