2/5*h=18

Solution for 2/5*h=18 equation:

2/5*h=18

We move all terms to the left:

2/5*h-(18)=0


Domain of the equation: 5*h!=0

h!=0/1

h!=0

h∈R


We multiply all the terms by the denominator


-18*5*h+2=0

Wy multiply elements

-90h*h+2=0

Wy multiply elements

-90h^2+2=0

a = -90; b = 0; c = +2;
Δ = b2-4ac
Δ = 02-4·(-90)·2
Δ = 720
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$h_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$h_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{720}=\sqrt{144*5}=\sqrt{144}*\sqrt{5}=12\sqrt{5}$
$h_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-12\sqrt{5}}{2*-90}=\frac{0-12\sqrt{5}}{-180}
=-\frac{12\sqrt{5}}{-180}
=-\frac{\sqrt{5}}{-15}
$
$h_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+12\sqrt{5}}{2*-90}=\frac{0+12\sqrt{5}}{-180}
=\frac{12\sqrt{5}}{-180}
=\frac{\sqrt{5}}{-15}
$