(x)(x+7)=(4)(15)

Solution for (x)(x+7)=(4)(15) equation:

(x)(x+7)=(4)(15)

We move all terms to the left:

(x)(x+7)-((4)(15))=0

determiningTheFunctionDomain
x(x+7)-415=0

We multiply parentheses

x^2+7x-415=0

a = 1; b = 7; c = -415;
Δ = b2-4ac
Δ = 72-4·1·(-415)
Δ = 1709
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{1709}}{2*1}=\frac{-7-\sqrt{1709}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7)+\sqrt{1709}}{2*1}=\frac{-7+\sqrt{1709}}{2}
$