145=x(7x+64)

Solution for 145=x(7x+64) equation:

145=x(7x+64)

We move all terms to the left:

145-(x(7x+64))=0


We calculate terms in parentheses: -(x(7x+64)), so:

x(7x+64)

We multiply parentheses

7x^2+64x

Back to the equation:

-(7x^2+64x)


We get rid of parentheses

-7x^2-64x+145=0

a = -7; b = -64; c = +145;
Δ = b2-4ac
Δ = -642-4·(-7)·145
Δ = 8156
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:

$\sqrt{\Delta}=\sqrt{8156}=\sqrt{4*2039}=\sqrt{4}*\sqrt{2039}=2\sqrt{2039}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-64)-2\sqrt{2039}}{2*-7}=\frac{64-2\sqrt{2039}}{-14}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-64)+2\sqrt{2039}}{2*-7}=\frac{64+2\sqrt{2039}}{-14}
$