Hey, there!!
Given that:
y = 3x.........(i)
[tex]y = {x}^{2} + 3x - 16.......(ii)[/tex]
Putting the value of y in equation (ii)
[tex] {3x}^{} = {x}^{2} + 3x - 16[/tex]
[tex] {x }^{2} - 16[/tex]=0
[tex]( {x)}^{2} - {4}^{2} = 0[/tex]
[tex](x + 4)(x - 4) = 0[/tex]
Therefore,
Either Or
(x+4)=0 (x-4)=0
x= -4 x= 4
so, x= (+ -)4
And if you wanna get value of y, just keep value of x in equation (i).
y= 3x
y= (3×4) or (3×-4)
y= 12 or -12
{As it is the quadratic equation it has two values. }
Hope it helps....
