-2/5w-21=-7/10w

Solution for -2/5w-21=-7/10w equation:

-2/5w-21=-7/10w

We move all terms to the left:

-2/5w-21-(-7/10w)=0


Domain of the equation: 5w!=0

w!=0/5

w!=0

w∈R



Domain of the equation: 10w)!=0

w!=0/1

w!=0

w∈R


We get rid of parentheses

-2/5w+7/10w-21=0

We calculate fractions


(-20w)/50w^2+35w/50w^2-21=0

We multiply all the terms by the denominator


(-20w)+35w-21*50w^2=0

We add all the numbers together, and all the variables

35w+(-20w)-21*50w^2=0

Wy multiply elements

-1050w^2+35w+(-20w)=0

We get rid of parentheses

-1050w^2+35w-20w=0

We add all the numbers together, and all the variables

-1050w^2+15w=0

a = -1050; b = 15; c = 0;
Δ = b2-4ac
Δ = 152-4·(-1050)·0
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-15}{2*-1050}=\frac{-30}{-2100}
=1/70
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+15}{2*-1050}=\frac{0}{-2100}
=0
$