(7x+4)(1-x)=0

Solution for (7x+4)(1-x)=0 equation:

(7x+4)(1-x)=0

We add all the numbers together, and all the variables

(7x+4)(-1x+1)=0

We multiply parentheses ..

(-7x^2+7x-4x+4)=0

We get rid of parentheses

-7x^2+7x-4x+4=0

We add all the numbers together, and all the variables

-7x^2+3x+4=0

a = -7; b = 3; c = +4;
Δ = b2-4ac
Δ = 32-4·(-7)·4
Δ = 121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{121}=11$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-11}{2*-7}=\frac{-14}{-14}
=1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+11}{2*-7}=\frac{8}{-14}
=-4/7
$