1+25y-(5y+5y*y)=10

Solution for 1+25y-(5y+5y*y)=10 equation:

1+25y-(5y+5y*y)=10

We move all terms to the left:

1+25y-(5y+5y*y)-(10)=0

We add all the numbers together, and all the variables

25y-(+5y+5y*y)+1-10=0

We add all the numbers together, and all the variables

25y-(+5y+5y*y)-9=0

We get rid of parentheses

25y-5y-5y*y-9=0

We add all the numbers together, and all the variables

20y-5y*y-9=0

Wy multiply elements

-5y^2+20y-9=0

a = -5; b = 20; c = -9;
Δ = b2-4ac
Δ = 202-4·(-5)·(-9)
Δ = 220
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{220}=\sqrt{4*55}=\sqrt{4}*\sqrt{55}=2\sqrt{55}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-2\sqrt{55}}{2*-5}=\frac{-20-2\sqrt{55}}{-10}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+2\sqrt{55}}{2*-5}=\frac{-20+2\sqrt{55}}{-10}
$