Tìm x: √x^2 = 7

tìm x
a)$\sqrt{{\mathrm{x}}^2}=7$
b) $\sqrt{4{\mathrm{x}}^2}=6$​
c)$\sqrt{{\mathrm{x}}^2}=\left|-8\right|$
d)$\sqrt{9{\mathrm{x}}^2}=\left|-12\right|$​