Download presentation

1
**Standardized Test Practice**

EXAMPLE 3 Standardized Test Practice SOLUTION 7p + 13 = 9p – 5 Write original equation. 13 = 2p – 5 Subtract 7p from each side. 18 = 2p Add 5 to each side. 9 = p Divide each side by 2. ANSWER The correct answer is D

2
**Standardized Test Practice**

EXAMPLE 3 Standardized Test Practice CHECK 7p + 13 = 9p – 5 Write original equation. 7(9) (9) – 5 = ? Substitute 9 for p. – 5 = ? Multiply. 76 = 76 Solution checks.

3
**Solve an equation using the distributive property**

EXAMPLE 4 Solve an equation using the distributive property Solve 3(5x – 8) = – 2(– x + 7) – 12x. 3(5x – 8) = – 2(– x + 7) – 12x Write original equation. 15x – 24 = 2x – 14 – 12x Distributive property 15x – 24 = – 10x – 14 Combine like terms. 25x – 24 = –14 Add 10x to each side. 25x = 10 Add 24 to each side. x = 2 5 Divide each side by 25 and simplify. ANSWER The solution 2 5

4
**Solve an equation using the distributive property**

EXAMPLE 4 Solve an equation using the distributive property CHECK 3 ( – 8) – 2(– ) – 12 2 5 = ? 2 5 Substitute for x. 3( – 6) –14 – 4 5 = ? 24 Simplify. – 18 = – 18 Solution checks.

5
EXAMPLE 5 Solve a work problem Car Wash It takes you 8 minutes to wash a car and it takes a friend 6 minutes to wash a car. How long does it take the two of you to wash 7 cars if you work together? SOLUTION STEP 1 Write a verbal model. Then write an equation.

6
**Solve the equation for t. STEP 2 1 8 t + t = 7 6 24( t + t) = 24 (7) 1 **

EXAMPLE 5 Solve a work problem Solve the equation for t. STEP 2 1 8 t t = 7 6 Write equation. 24( t + t) = 24 (7) 1 8 6 Multiply each side by the LCD, 24. 3t + 4t = 168 Distributive property 7t = 168 Combine like terms. t = 24 Divide each side by 7. ANSWER It will take 24 minutes to wash 7 cars if you work together.

7
EXAMPLE 5 Solve a work problem CHECK You wash = 3 cars and your friend washes = 4 cars in 24 minutes. Together, you wash 7 cars. 1 6 8

8
**Solve the equation. Check your solution.**

GUIDED PRACTICE for Examples 3, 4, and 5 Solve the equation. Check your solution. 5. –2x + 9 = 2x – 7 SOLUTION –2x + 9 = 2x – 7 Write original equation. –4x + 9 = – 7 Subtract 2x from each side. –4x = –16 subtract 9 from each side. x = 4 Divide each side by –4. ANSWER The correct answer is 4.

9
**GUIDED PRACTICE for Examples 3, 4, and 5 CHECK –2(4) + 9 2(4) – 7 =**

–2(4) (4) – 7 ? = Substitute 4 for x. –8 + 9 = 8 – 7 Simplify 1 = 1 Solution check

10
**Solve the equation. Check your solution.**

GUIDED PRACTICE for Examples 3, 4, and 5 Solve the equation. Check your solution. – x = – 6x + 15 SOLUTION 10 – x = – 6x + 15 Write original equation. 10 + 5x = 15 Add 6x to each side. 5x = 5 subtract 10 from each side. x = 1 Divide each side by –5. ANSWER The correct answer is 1.

11
**GUIDED PRACTICE for Examples 3, 4, and 5 CHECK 10 –1 – 6(1) + 15 =**

10 –1 – 6(1) + 15 ? = Substitute 1 for x. 9 = 9 Solution check.

12
**Solve the equation. Check your solution.**

GUIDED PRACTICE for Examples 3, 4, and 5 Solve the equation. Check your solution. (x + 2) = 5(x + 4) SOLUTION 3(x + 2) = 5(x + 4) Write original equation. 3x + 6 = 5x + 20 Distributive property. 6 = 2x + 20 Subtract 3x from each side. – 14 = 2x Subtract 20 from each side. x = –7 Solve for x ANSWER The solution is –7.

13
**GUIDED PRACTICE for Examples 3, 4, and 5 CHECK 3((–7) + 2) 5 (–7 + 4)**

3((–7) + 2) (–7 + 4) ? = Substitute – 7 for x. 3(–5) (–3) ? = Simplify – 15 = –15 Solution check.

14
**Solve the equation. Check your solution.**

GUIDED PRACTICE for Examples 3, 4, and 5 Solve the equation. Check your solution. 8. – 4(2x + 5) = 2(– x – 9) – 4x SOLUTION – 4(2x + 5) = 2(–x – 9) – 4x Write original equation. –8x – 20 = –2x – 18 – 4x Distributive property. –8x – 20 = –6x – 18 Combine like term. –20 = 2x – 18 Add 8x to each side. –2 = 2x Add 18 to each side. x = –1 Divide each side by 2.

15
**GUIDED PRACTICE for Examples 3, 4, and 5 ANSWER The solution x = – 1**

CHECK –4 (2(–1) + 5 ) 2(–(–1) – 9) – 4(–1) = ? Substitute –1 for x. – 4( – 2 + 5) (– 8) + 4 = ? Simplify. – 4( 3) (–16) + 4 = ? – = –12 Solution checks.

16
**Solve the equation. Check your solution.**

GUIDED PRACTICE for Examples 3, 4, and 5 Solve the equation. Check your solution. x x = 39 1 4 2 5 9. SOLUTION x x = 39 1 4 2 5 Write original equation. 13x 20 = 39 Combine like term. 13x = Multiply each side by 20. x = 60 Divide each side to 13. ANSWER The correct answer is 60

17
**GUIDED PRACTICE for Examples 3, 4, and 5 CHECK x + x = 39 1 4 2 5 1 4**

Write original equation. 1 4 (60) (60) 2 5 ? = Substitute 60 for x. ? = 120 5 + 60 4 39 Simplify 39 = 39 Solution checks.

18
GUIDED PRACTICE for Examples 3, 4, and 5 Solve the equation. Check your solution. x = x – 1 2 3 5 6 ANSWER The correct answer is 4

19
GUIDED PRACTICE for Examples 3, 4, and 5 What If? In Example 5, suppose it takes you 9 minutes to wash a car and it takes your friend 12 minutes to wash a car. How long does it take the two of you to wash 7 cars if you work together? 11. SOLUTION STEP 1 Write a verbal model. Then write an equation. t min 1 car 9 min 12 min t min = 7 +

20
**Solve the equation for t. STEP 2 1 9 t + t = 7 12 36( t + t) = 36 (7) **

GUIDED PRACTICE for Examples 3, 4, and 5 Solve the equation for t. STEP 2 1 9 t t = 7 12 Write equation. 36( t + t) = 36 (7) 1 9 12 Multiply each side by the LCD, 24. 4t + 3t = 252 Distributive property 7t = 252 Combine like terms. t = 36 Divide each side by 7. ANSWER It will take 36 minutes to wash 7 cars if you work together.

21
EXAMPLE 5 GUIDED PRACTICE for Examples 3, 4, and 5 CHECK You wash = 4 cars and your friend washes = 3 cars in 36 minutes. Together, you wash 7 cars. 1 12 9

Similar presentations

© 2019 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google