x2-8x+7=(x-1)

Solution for x2-8x+7=(x-1) equation:

x2-8x+7=(x-1)

We move all terms to the left:

x2-8x+7-((x-1))=0

We add all the numbers together, and all the variables

x^2-8x-((x-1))+7=0


We calculate terms in parentheses: -((x-1)), so:

(x-1)

We get rid of parentheses

x-1

Back to the equation:

-(x-1)


We get rid of parentheses

x^2-8x-x+1+7=0

We add all the numbers together, and all the variables

x^2-9x+8=0

a = 1; b = -9; c = +8;
Δ = b2-4ac
Δ = -92-4·1·8
Δ = 49
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{49}=7$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-7}{2*1}=\frac{2}{2}
=1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+7}{2*1}=\frac{16}{2}
=8
$