Question

Solve the equation. If necessary round to the nearest tenth 4x^2=81
A. 2.25, -2.25
B. 9, -9
C. 20.25, -20.25
D. 4.5, -4.5

Answer 1

$4x^2=81 \\ x^2=81/4 \\ x^2 = 20.25 \\ x=б \sqrt{20.25} \\ x=б4.5$


D. 4.5, -4.5