21p^2+15p+8=8

Solution for 21p^2+15p+8=8 equation:

21p^2+15p+8=8

We move all terms to the left:

21p^2+15p+8-(8)=0

We add all the numbers together, and all the variables

21p^2+15p=0

a = 21; b = 15; c = 0;
Δ = b2-4ac
Δ = 152-4·21·0
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-15}{2*21}=\frac{-30}{42}
=-5/7
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+15}{2*21}=\frac{0}{42}
=0
$