64x^2-9=40

Solution for 64x^2-9=40 equation:

64x^2-9=40

We move all terms to the left:

64x^2-9-(40)=0

We add all the numbers together, and all the variables

64x^2-49=0

a = 64; b = 0; c = -49;
Δ = b2-4ac
Δ = 02-4·64·(-49)
Δ = 12544
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{12544}=112$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-112}{2*64}=\frac{-112}{128}
=-7/8
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+112}{2*64}=\frac{112}{128}
=7/8
$