Question

Find the positive solution and please explain how ;4;

Answer 1

(x + 2)² - 10 = 0 (assuming it's equal to zero)

Expand the binomial: (x + y)² = x² + 2xy + y²
Thus, x² + 4x + 4 - 10 = 0
x² + 4x - 6 = 0


`x = (-4 +_- √(16 + 24))/(2)` (by quadratic formula)

`= (-4 +_- √(40))/(2)`

`= (-4 +_- 2√(10))/(2)`

`= -2 + √(10)`, since we're taking the positive solution.