490t^2-640=0

Solution for 490t^2-640=0 equation:

490t^2-640=0

a = 490; b = 0; c = -640;
Δ = b2-4ac
Δ = 02-4·490·(-640)
Δ = 1254400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1254400}=1120$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-1120}{2*490}=\frac{-1120}{980}
=-1+1/7
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+1120}{2*490}=\frac{1120}{980}
=1+1/7
$