(4c+5)(7c-6)=-

Solution for (4c+5)(7c-6)=- equation:

(4c+5)(7c-6)=-

We move all terms to the left:

(4c+5)(7c-6)-(-)=0

We add all the numbers together, and all the variables

(4c+5)(7c-6)-0=0

We add all the numbers together, and all the variables

(4c+5)(7c-6)=0

We multiply parentheses ..

(+28c^2-24c+35c-30)=0

We get rid of parentheses

28c^2-24c+35c-30=0

We add all the numbers together, and all the variables

28c^2+11c-30=0

a = 28; b = 11; c = -30;
Δ = b2-4ac
Δ = 112-4·28·(-30)
Δ = 3481
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3481}=59$
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(11)-59}{2*28}=\frac{-70}{56}
=-1+1/4
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(11)+59}{2*28}=\frac{48}{56}
=6/7
$