Question

3/7 x^2 -7 = 21

Answer 1

3/7 x^2 = 28

x^2 = 7/3 * 28

\[x = \pm \sqrt{196/3}\]

Answer 2

\[x = \pm14/\sqrt{3}\]

Answer 3

x^2 -49/3 = 49
x^2=49 +49/3=(147+49)/3=196/3
x=+-sqrta96/3=+-14sqrt3/3