35r^2-r-12=0

Solution for 35r^2-r-12=0 equation:

35r^2-r-12=0

We add all the numbers together, and all the variables

35r^2-1r-12=0

a = 35; b = -1; c = -12;
Δ = b2-4ac
Δ = -12-4·35·(-12)
Δ = 1681
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1681}=41$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-41}{2*35}=\frac{-40}{70}
=-4/7
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+41}{2*35}=\frac{42}{70}
=3/5
$