(11d+4)(9d+7)=0.

Solution for (11d+4)(9d+7)=0. equation:

(11d+4)(9d+7)=0.

We multiply parentheses ..

(+99d^2+77d+36d+28)=0

We get rid of parentheses

99d^2+77d+36d+28=0

We add all the numbers together, and all the variables

99d^2+113d+28=0

a = 99; b = 113; c = +28;
Δ = b2-4ac
Δ = 1132-4·99·28
Δ = 1681
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1681}=41$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(113)-41}{2*99}=\frac{-154}{198}
=-7/9
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(113)+41}{2*99}=\frac{-72}{198}
=-4/11
$