X2+28x+147=0

Solution for X2+28x+147=0 equation:

X2+28X+147=0

We add all the numbers together, and all the variables

X^2+28X+147=0

a = 1; b = 28; c = +147;
Δ = b2-4ac
Δ = 282-4·1·147
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(28)-14}{2*1}=\frac{-42}{2}
=-21
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+14}{2*1}=\frac{-14}{2}
=-7
$