1/5(15c)=c+7

Solution for 1/5(15c)=c+7 equation:

1/5(15c)=c+7

We move all terms to the left:

1/5(15c)-(c+7)=0


Domain of the equation: 515c!=0

c!=0/515

c!=0

c∈R


We get rid of parentheses

1/515c-c-7=0

We multiply all the terms by the denominator


-c*515c-7*515c+1=0

Wy multiply elements

-515c^2-3605c+1=0

a = -515; b = -3605; c = +1;
Δ = b2-4ac
Δ = -36052-4·(-515)·1
Δ = 12998085
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3605)-\sqrt{12998085}}{2*-515}=\frac{3605-\sqrt{12998085}}{-1030}
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3605)+\sqrt{12998085}}{2*-515}=\frac{3605+\sqrt{12998085}}{-1030}
$