(x+2)(0.5x)=84

Solution for (x+2)(0.5x)=84 equation:

(x+2)(0.5x)=84

We move all terms to the left:

(x+2)(0.5x)-(84)=0

We add all the numbers together, and all the variables

(x+2)(+0.5x)-84=0

We multiply parentheses ..

(+0x^2+0x)-84=0

We get rid of parentheses

0x^2+0x-84=0

We add all the numbers together, and all the variables

x^2+x-84=0

a = 1; b = 1; c = -84;
Δ = b2-4ac
Δ = 12-4·1·(-84)
Δ = 337
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{-(1)-\sqrt{337}}{2*1}=\frac{-1-\sqrt{337}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{337}}{2*1}=\frac{-1+\sqrt{337}}{2}
$