45=(3.5x+3.5x)+x2

Solution for 45=(3.5x+3.5x)+x2 equation:

45=(3.5x+3.5x)+x2

We move all terms to the left:

45-((3.5x+3.5x)+x2)=0

We add all the numbers together, and all the variables

-((+7x)+x2)+45=0


We calculate terms in parentheses: -((+7x)+x2), so:

(+7x)+x2

We add all the numbers together, and all the variables

x^2+(+7x)

We get rid of parentheses

x^2+7x

Back to the equation:

-(x^2+7x)


We get rid of parentheses

-x^2-7x+45=0

We add all the numbers together, and all the variables

-1x^2-7x+45=0

a = -1; b = -7; c = +45;
Δ = b2-4ac
Δ = -72-4·(-1)·45
Δ = 229
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-7)-\sqrt{229}}{2*-1}=\frac{7-\sqrt{229}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+\sqrt{229}}{2*-1}=\frac{7+\sqrt{229}}{-2}
$