3x^2+21x-5x-35=0

Solution for 3x^2+21x-5x-35=0 equation:

3x^2+21x-5x-35=0

We add all the numbers together, and all the variables

3x^2+16x-35=0

a = 3; b = 16; c = -35;
Δ = b2-4ac
Δ = 162-4·3·(-35)
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-26}{2*3}=\frac{-42}{6}
=-7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+26}{2*3}=\frac{10}{6}
=1+2/3
$