How do you solve the equation 3sqrt(x) = x- 4?

Nov 27, 2016

$x = 16$

Explanation:

$3 \sqrt{x} = x - 4$

${\left(3 \sqrt{x}\right)}^{2} = {\left(x - 4\right)}^{2}$

$9 \left(x\right) = {x}^{2} - 8 x + 16$

$0 = {x}^{2} - 17 x + 16$

$0 = \left(x - 16\right) \left(x - 1\right)$

$x = 16 \mathmr{and} 1$

Check:

3sqrt(16) + 3 =^? 16 - 1

3(4) + 3 = 15" "color(green)(√)

3sqrt(1) + 3 =^? 1 - 1

$3 + 3 \ne 0 \text{ } \textcolor{red}{\times}$

Hopefully this helps!