4x*5x=7-1+4

Solution for 4x*5x=7-1+4 equation:

4x*5x=7-1+4

We move all terms to the left:

4x*5x-(7-1+4)=0

We add all the numbers together, and all the variables

4x*5x-10=0

Wy multiply elements

20x^2-10=0

a = 20; b = 0; c = -10;
Δ = b2-4ac
Δ = 02-4·20·(-10)
Δ = 800
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:

$\sqrt{\Delta}=\sqrt{800}=\sqrt{400*2}=\sqrt{400}*\sqrt{2}=20\sqrt{2}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-20\sqrt{2}}{2*20}=\frac{0-20\sqrt{2}}{40}
=-\frac{20\sqrt{2}}{40}
=-\frac{\sqrt{2}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+20\sqrt{2}}{2*20}=\frac{0+20\sqrt{2}}{40}
=\frac{20\sqrt{2}}{40}
=\frac{\sqrt{2}}{2}
$