Question

I need help on showing work but it can’t be substitution! :(

Answer 1

(x - 5)^2 = 81

x^2 - 10x + 25 = 81

x^2 - 10x -56 = 0

The equation of bhaskara is

`x=\frac{-b\text{ }\pm\sqrt[]{b^2-4ac}}{2a}`

In this case, we have, a = 1, b = -10 and c = -56

Therefore:

`x_+=\frac{10\text{ +}\sqrt[]{100+4\cdot56}}{2}=14_{},x_-=\text{ }\frac{10-\sqrt[]{100+4\cdot56}}{2}=\text{ -4}`