4a^2+7a-15=

Solution for 4a^2+7a-15= equation:

4a^2+7a-15=

We move all terms to the left:

4a^2+7a-15-()=0

We add all the numbers together, and all the variables

4a^2+7a=0

a = 4; b = 7; c = 0;
Δ = b2-4ac
Δ = 72-4·4·0
Δ = 49
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{49}=7$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(7)-7}{2*4}=\frac{-14}{8}
=-1+3/4
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7)+7}{2*4}=\frac{0}{8}
=0
$