8x^2-21x+10=-16x^2-71x-15

Solution for 8x^2-21x+10=-16x^2-71x-15 equation:

8x^2-21x+10=-16x^2-71x-15

We move all terms to the left:

8x^2-21x+10-(-16x^2-71x-15)=0

We get rid of parentheses

8x^2+16x^2+71x-21x+15+10=0

We add all the numbers together, and all the variables

24x^2+50x+25=0

a = 24; b = 50; c = +25;
Δ = b2-4ac
Δ = 502-4·24·25
Δ = 100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{100}=10$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(50)-10}{2*24}=\frac{-60}{48}
=-1+1/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(50)+10}{2*24}=\frac{-40}{48}
=-5/6
$