5/7*x=1

Solution for 5/7*x=1 equation:

5/7*x=1

We move all terms to the left:

5/7*x-(1)=0


Domain of the equation: 7*x!=0

x!=0/1

x!=0

x∈R


We multiply all the terms by the denominator


-1*7*x+5=0

Wy multiply elements

-7x*x+5=0

Wy multiply elements

-7x^2+5=0

a = -7; b = 0; c = +5;
Δ = b2-4ac
Δ = 02-4·(-7)·5
Δ = 140
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{140}=\sqrt{4*35}=\sqrt{4}*\sqrt{35}=2\sqrt{35}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{35}}{2*-7}=\frac{0-2\sqrt{35}}{-14}
=-\frac{2\sqrt{35}}{-14}
=-\frac{\sqrt{35}}{-7}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{35}}{2*-7}=\frac{0+2\sqrt{35}}{-14}
=\frac{2\sqrt{35}}{-14}
=\frac{\sqrt{35}}{-7}
$