-7(1/8)x-3/4=-20

Solution for -7(1/8)x-3/4=-20 equation:

-7(1/8)x-3/4=-20

We move all terms to the left:

-7(1/8)x-3/4-(-20)=0


Domain of the equation: 8)x!=0

x!=0/1

x!=0

x∈R


We add all the numbers together, and all the variables

-7(+1/8)x-3/4-(-20)=0

We add all the numbers together, and all the variables

-7(+1/8)x+20-3/4=0

We multiply parentheses

-7x^2+20-3/4=0

We multiply all the terms by the denominator


-7x^2*4-3+20*4=0

We add all the numbers together, and all the variables

-7x^2*4+77=0

Wy multiply elements

-28x^2+77=0

a = -28; b = 0; c = +77;
Δ = b2-4ac
Δ = 02-4·(-28)·77
Δ = 8624
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{8624}=\sqrt{784*11}=\sqrt{784}*\sqrt{11}=28\sqrt{11}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-28\sqrt{11}}{2*-28}=\frac{0-28\sqrt{11}}{-56}
=-\frac{28\sqrt{11}}{-56}
=-\frac{\sqrt{11}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+28\sqrt{11}}{2*-28}=\frac{0+28\sqrt{11}}{-56}
=\frac{28\sqrt{11}}{-56}
=\frac{\sqrt{11}}{-2}
$