1/7r+3(1/7r)=357

Solution for 1/7r+3(1/7r)=357 equation:

1/7r+3(1/7r)=357

We move all terms to the left:

1/7r+3(1/7r)-(357)=0


Domain of the equation: 7r!=0

r!=0/7

r!=0

r∈R



Domain of the equation: 7r)!=0

r!=0/1

r!=0

r∈R


We add all the numbers together, and all the variables

1/7r+3(+1/7r)-357=0

We multiply parentheses

1/7r+3r-357=0

We multiply all the terms by the denominator


3r*7r-357*7r+1=0

Wy multiply elements

21r^2-2499r+1=0

a = 21; b = -2499; c = +1;
Δ = b2-4ac
Δ = -24992-4·21·1
Δ = 6244917
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2499)-\sqrt{6244917}}{2*21}=\frac{2499-\sqrt{6244917}}{42}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2499)+\sqrt{6244917}}{2*21}=\frac{2499+\sqrt{6244917}}{42}
$