X+2x(2+7x)=42

Solution for X+2x(2+7x)=42 equation:

X+2X(2+7X)=42

We move all terms to the left:

X+2X(2+7X)-(42)=0

We add all the numbers together, and all the variables

X+2X(7X+2)-42=0

We multiply parentheses

14X^2+X+4X-42=0

We add all the numbers together, and all the variables

14X^2+5X-42=0

a = 14; b = 5; c = -42;
Δ = b2-4ac
Δ = 52-4·14·(-42)
Δ = 2377
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{-(5)-\sqrt{2377}}{2*14}=\frac{-5-\sqrt{2377}}{28}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+\sqrt{2377}}{2*14}=\frac{-5+\sqrt{2377}}{28}
$