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5 votes
5 votes
Solve for x: (3x-2)(x+1)=18x+4

User Matthias Preu
by
3.4k points

2 Answers

8 votes
8 votes
answer: x= 7.752
Step-by-step explanation:
User Burk
by
3.1k points
14 votes
14 votes

Answer:

x = 6 , -1/3

Step-by-step explanation:

Use foil method

(3x -2)(x + 1) = 3x*x + 3x*1 + (-2)*x + (-2)*1

= 3x² + 3x - 2x - 2 {Combine like terms}

=3x² + x - 2

(3x -2)(x + 1) = 18x + 4

3x² + x -2 = 18x + 4

Subtract 18x to both sides

3x² + x - 18x - 2 = 4

3x² - 17x - 2 = 4

Subtract 4 from both sides

3x² - 17x -2 -4 = 0

3x² - 17x - 6 = 0

Sum = -17

Product = (-6)*3 = -18

Factors = 1 , (-18) {1*(-18)=-18 ; 1 +(-18) = -17}

3x² - 18x + x - 6 = 0

3x(x - 6) + (x -6) = 0

(x - 6)(3x + 1) = 0

x - 6 = 0 ; 3x + 1 = 0

x = 6 ; 3x = -1

x = -1/3

x = 6 , (-1/3)

User DuuEyn
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3.1k points