154=22/7*r^2

Solution for 154=22/7*r^2 equation:

154=22/7r^2

We move all terms to the left:

154-(22/7r^2)=0


Domain of the equation: 7r^2)!=0

r!=0/1

r!=0

r∈R


We get rid of parentheses

-22/7r^2+154=0

We multiply all the terms by the denominator


154*7r^2-22=0

Wy multiply elements

1078r^2-22=0

a = 1078; b = 0; c = -22;
Δ = b2-4ac
Δ = 02-4·1078·(-22)
Δ = 94864
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{94864}=308$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-308}{2*1078}=\frac{-308}{2156}
=-1/7
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+308}{2*1078}=\frac{308}{2156}
=1/7
$