21x^2=-150x

Solution for 21x^2=-150x equation:

21x^2=-150x

We move all terms to the left:

21x^2-(-150x)=0

We get rid of parentheses

21x^2+150x=0

a = 21; b = 150; c = 0;
Δ = b2-4ac
Δ = 1502-4·21·0
Δ = 22500
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{22500}=150$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(150)-150}{2*21}=\frac{-300}{42}
=-7+1/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(150)+150}{2*21}=\frac{0}{42}
=0
$