Question

4-x suare= -16 what is the answer

Answer 1

$4-x^2=-16\\\\ x^2=20\\\\ x=\sqrt{20} \vee x=-\sqrt{20}\\\\ x=2\sqrt5 \vee x=-2\sqrt5$

Answer 2

x = ± 2√5

subtract 4 from both sides

- x² = - 16 - 4 = - 20

multiply both sides by ( - 1)

x² = 20

Take the square root of both sides

x = ± √20 ( note plus or minus)

x = ± √4 ×  5 = ± √4 × √5 = ± 2√5