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36 votes
36 votes
How would I solve -3 + √ 3x+7 =x

User Eastonsuo
by
3.2k points

1 Answer

20 votes
20 votes

The equation is given as;

-3 + √ {3x + 7} = x

Take -3 to the right side of the equation

√ {3x + 7} = x+3

Eliminate the square-root on the left side of the equation by squaring both sides

3 x + 7 = {x + 3}^2

Expand the right-hand side

3x + 7 = x^2 + 6x + 9

Collect like terms

0=x^2 +6x -3x +9-7

0= x^2 +3x +2

Re-write the equation as;

x^2 + 3x +2 =0

Factorize to find the value of x

x^2 + x + 2x + 2 = 0

x{x + 1} + 2{ x+ 1} =0

{x+2} {x+ 1} = 0

Solve for x

x+ 2 = 0

x = -2

or

x+ 1 = 0

x = -1

Answer

x = -2 or -1

User Gyandeep Sharma
by
2.3k points
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