Question

How do you solve by completing the square: `x^2 - 14x = 51`?

Answer 1

This is the way:

`x^2-14x=51rArrx^2-14x+7^2-7^2=51rArr`

`x^2-14x+49=51+49rArr(x-7)^2=100rArr`

`x-7=+-10rArrx=7+-10rArr`

`x_1=7-10=-3`

`x_2=7+10=17`.