49r^2-7r=30

Solution for 49r^2-7r=30 equation:

49r^2-7r=30

We move all terms to the left:

49r^2-7r-(30)=0

a = 49; b = -7; c = -30;
Δ = b2-4ac
Δ = -72-4·49·(-30)
Δ = 5929
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5929}=77$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-7)-77}{2*49}=\frac{-70}{98}
=-5/7
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+77}{2*49}=\frac{84}{98}
=6/7
$