(-3j+4)(7j-6)=0

Solution for (-3j+4)(7j-6)=0 equation:

(-3j+4)(7j-6)=0

We multiply parentheses ..

(-21j^2+18j+28j-24)=0

We get rid of parentheses

-21j^2+18j+28j-24=0

We add all the numbers together, and all the variables

-21j^2+46j-24=0

a = -21; b = 46; c = -24;
Δ = b2-4ac
Δ = 462-4·(-21)·(-24)
Δ = 100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$j_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$j_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{100}=10$
$j_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(46)-10}{2*-21}=\frac{-56}{-42}
=1+1/3
$
$j_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(46)+10}{2*-21}=\frac{-36}{-42}
=6/7
$