7/10c-8-1/2c=-18

Solution for 7/10c-8-1/2c=-18 equation:

7/10c-8-1/2c=-18

We move all terms to the left:

7/10c-8-1/2c-(-18)=0


Domain of the equation: 10c!=0

c!=0/10

c!=0

c∈R



Domain of the equation: 2c!=0

c!=0/2

c!=0

c∈R


We add all the numbers together, and all the variables

7/10c-1/2c+10=0

We calculate fractions


14c/20c^2+(-10c)/20c^2+10=0

We multiply all the terms by the denominator


14c+(-10c)+10*20c^2=0

Wy multiply elements

200c^2+14c+(-10c)=0

We get rid of parentheses

200c^2+14c-10c=0

We add all the numbers together, and all the variables

200c^2+4c=0

a = 200; b = 4; c = 0;
Δ = b2-4ac
Δ = 42-4·200·0
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-4}{2*200}=\frac{-8}{400}
=-1/50
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+4}{2*200}=\frac{0}{400}
=0
$