-8.75=8.75+12.99038106x-4.9x^2

Solution for -8.75=8.75+12.99038106x-4.9x^2 equation:

-8.75=8.75+12.99038106x-4.9x^2

We move all terms to the left:

-8.75-(8.75+12.99038106x-4.9x^2)=0

We get rid of parentheses

4.9x^2-12.99038106x-8.75-8.75=0

We add all the numbers together, and all the variables

4.9x^2-12.99038106x-17.5=0

a = 4.9; b = -12.99038106; c = -17.5;
Δ = b2-4ac
Δ = -12.990381062-4·4.9·(-17.5)
Δ = 511.75000008401
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12.99038106)-\sqrt{511.75000008401}}{2*4.9}=\frac{12.99038106-\sqrt{511.75000008401}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12.99038106)+\sqrt{511.75000008401}}{2*4.9}=\frac{12.99038106+\sqrt{511.75000008401}}{9.8}
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