Hey there!!
Equations given :
y = x² - x - 20 -------- ( 1 )
y = 3x - 15 ------------ ( 2 )
Now, lets first solve for the 1st equation ...
... x² - x - 20
We can write -x as -5x + 4x
... x² + 4x - 5x - 20
... x ( x + 4 ) - 5 ( x + 4 )
... ( x - 5 ) ( x + 4 )
y = ( x - 5 ) ( x - 4 )
Now, let's solve the second equation ...
y = 3x - 15
... y = 3 ( x - 5 )
We have two equations, now getting them together..
3 ( x - 5 ) = ( x - 5 ) ( x - 4 )
Divide by x-5 on both sides
3 = x - 4
Add 4 on both sides
x = 7
The value of x is 7
Now substituting this, we get the value of y
We have,
y = 3x - 15
... y = 3(7 ) - 15
... y = 21 - 15
... y = 6
Hence, the ordered pair is ( 7 , 6 )
Hope my answer helps!
