Question

The solution to the following pair of simultaneous equations is: y = x^2 + x-2 and y = 2x + 10​

Answer 1

y = x^2 + x-2

y= x^2 +2x-x -2

y= x(x+2) -1(x+2)

y= (x+2)(x-1)

y = 2x + 10

x^2 + x-2= 2x+10

x^2 +x-2x-2-10=0

x^2 -x -12=0

x^2 - 4x+3x -12=0

x(x-4) +3(x-4)=0

(x-4)(x+3)=0

x= 4, -3

when x= 4

y= (x+2)(x-1)

y= (4+2)(4-1)

y= 6*3=18

when x= -3

y= (x+2)(x-1)

y= (-3+2)(-3-1)

y= -1x-4

y= 4