Answer to Question #85663 in Algebra for Kailyn

Question

Which strategy is the most appropriate strategy to solve x^2-8x=242?

Answer 1

The most appropriate strategy to solve x^2-8x=242 is completing the square.

Given quadratic equation x^2-8x=242

Write equation in the form x^2+2ax+a^2=(a+x)^2

Solve for a,

2ax=-8x then we get the value of a is -4

by adding a^2=(-4)^2 to both the sides of given equation,

then we get x^2-8x+(-4)^2 = 242 +(-4)^2

it implies (x-4)^2 = 258

so x-4 = ±√258

therefore x = √258+4 and x = -√258+4

Hence the two zeros of quadratic equation x^2-8x = 242 are x = √258+4, x = -√258 +4.