7x2+26x+15=(x+)(x+)

Solution for 7x2+26x+15=(x+)(x+) equation:

7x^2+26x+15=(x+)(x+)

We move all terms to the left:

7x^2+26x+15-((x+)(x+))=0

We add all the numbers together, and all the variables

7x^2+26x-((+x)(+x))+15=0

We multiply parentheses ..

7x^2-((+x^2))+26x+15=0


We calculate terms in parentheses: -((+x^2)), so:

(+x^2)

We get rid of parentheses

x^2

Back to the equation:

-(x^2)


We add all the numbers together, and all the variables

6x^2+26x+15=0

a = 6; b = 26; c = +15;
Δ = b2-4ac
Δ = 262-4·6·15
Δ = 316
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:

$\sqrt{\Delta}=\sqrt{316}=\sqrt{4*79}=\sqrt{4}*\sqrt{79}=2\sqrt{79}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(26)-2\sqrt{79}}{2*6}=\frac{-26-2\sqrt{79}}{12}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(26)+2\sqrt{79}}{2*6}=\frac{-26+2\sqrt{79}}{12}
$