You need to put the x or y value in the other equation ; For example excersize a It given that Y=x^2+3x-1 Then you put it on the first equation : x+x^2+3x-1=4 And then you solve it x+x^2+3x-1-4=0 4x+x^2-5=0 We will make the order to seem easier x^2+4x-5=0 x1=-5 x2=1 Then you put the x1,2 that you found on the second equation : y=(-5)^2+3*(-5)-1=9 y=1^2+3*1-1=3 For summary : x1=-5 x2=1 y1=9 y2=3