3.5t=1.2t^2

Solution for 3.5t=1.2t^2 equation:

3.5t=1.2t^2

We move all terms to the left:

3.5t-(1.2t^2)=0

We get rid of parentheses

-1.2t^2+3.5t=0

a = -1.2; b = 3.5; c = 0;
Δ = b2-4ac
Δ = 3.52-4·(-1.2)·0
Δ = 12.25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3.5)-\sqrt{12.25}}{2*-1.2}=\frac{-3.5-\sqrt{12.25}}{-2.4}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3.5)+\sqrt{12.25}}{2*-1.2}=\frac{-3.5+\sqrt{12.25}}{-2.4}
$