100=49y^2

Solution for 100=49y^2 equation:

100=49y^2

We move all terms to the left:

100-(49y^2)=0

a = -49; b = 0; c = +100;
Δ = b2-4ac
Δ = 02-4·(-49)·100
Δ = 19600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{19600}=140$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-140}{2*-49}=\frac{-140}{-98}
=1+3/7
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+140}{2*-49}=\frac{140}{-98}
=-1+3/7
$