F(x)=25x2-49

Solution for F(x)=25x2-49 equation:

(F)=25F^2-49

We move all terms to the left:

(F)-(25F^2-49)=0

We get rid of parentheses

-25F^2+F+49=0

a = -25; b = 1; c = +49;
Δ = b2-4ac
Δ = 12-4·(-25)·49
Δ = 4901
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{4901}=\sqrt{169*29}=\sqrt{169}*\sqrt{29}=13\sqrt{29}$
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-13\sqrt{29}}{2*-25}=\frac{-1-13\sqrt{29}}{-50}
$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+13\sqrt{29}}{2*-25}=\frac{-1+13\sqrt{29}}{-50}
$