Solve and check Solve and check x 82 49Solutionx82 49 It

Solve and check

Solution

(x+8)² = 49 ;
It means x² + 16 x + 64 = 49
x² + 16x + 15 = 0
x² + 15 x + x + 15 = 0
x(x+15) + 1(x+15) =0
(x+1) (x+15) = 0 which means
x= -1 or x=-15;

Verification:
Substituting x=-1 we get : (-1+8)² = 7² = 49 which is true;
Substituing x=-15 we get : (-15+8)² =(-7) ²  = 49 which is true

Note: If you are taking square root on both sides then do consider that square root of 49 is both +7 and -7;