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2 votes
How to solve 12x+7=5x-21

User Jim Nelson
by
8.3k points

2 Answers

6 votes

Answer:

x = -4

Explanation:

12x+7=5x-21

12x+7-5x=5x-21-5x [Subtract 5x from both sides]

7x + 7 = -21 [Combine like terms]

7x + 7 - 7= -21 - 7 [Subtract 7 from both sides]

7x = -28 [Combine like terms]

7x/7 = -28/7 [Divide both sides by 7]

x = -4 [Simplify]

CHECK:

Does 12x+7=5x-21 when x = -4?

12*(-4)+7=5*(-4)-21 ?

= 48 + 7 = -20 - 21 ?

- 41 = - 42 YES

User Tom Hale
by
7.9k points
1 vote

Explanation:

12x-5x = -21-17

7x = -38

x = -38/7

User Jorge Solis
by
8.4k points

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