9=3(5x2)

Solution for 9=3(5x2) equation:

9=3(5x^2)

We move all terms to the left:

9-(3(5x^2))=0

determiningTheFunctionDomain
-35x^2+9=0

a = -35; b = 0; c = +9;
Δ = b2-4ac
Δ = 02-4·(-35)·9
Δ = 1260
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1260}=\sqrt{36*35}=\sqrt{36}*\sqrt{35}=6\sqrt{35}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-6\sqrt{35}}{2*-35}=\frac{0-6\sqrt{35}}{-70}
=-\frac{6\sqrt{35}}{-70}
=-\frac{3\sqrt{35}}{-35}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+6\sqrt{35}}{2*-35}=\frac{0+6\sqrt{35}}{-70}
=\frac{6\sqrt{35}}{-70}
=\frac{3\sqrt{35}}{-35}
$