Solve these 2 equations simultaneously: 7x+y=1 and 2x squared - y=3

7x+y=1 (1)  ->   y= 2x² - 3 (3)

7x + 2x² -3-1=0 -> (2x-1)(x+4)=0 so 2x-1=0 so 2x=1 so x=0.5 and x+4=0 so x=-4

7(0.5)+y=1 so y=1-3.5 so y=-2.5 and 7(-4) +y=1 so -28+y=1 so y= 29

Full answer:

x=0.5 y=-2.5 and x=-4 y=29