(X-7)(2y-9)=0

Solution for (X-7)(2y-9)=0 equation:

(X-7)(2X-9)=0

We multiply parentheses ..

(+2X^2-9X-14X+63)=0

We get rid of parentheses

2X^2-9X-14X+63=0

We add all the numbers together, and all the variables

2X^2-23X+63=0

a = 2; b = -23; c = +63;
Δ = b2-4ac
Δ = -232-4·2·63
Δ = 25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25}=5$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-23)-5}{2*2}=\frac{18}{4}
=4+1/2
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-23)+5}{2*2}=\frac{28}{4}
=7
$