Question

x2 − x(√7−2) − 2√7 = 0

Answer 1

x²-x(√7-2)-2√7=0

D= (√7-2)²+4*2√7= 7-4√7+4+8√7= 7+4√7+4= (√7+2)²

x1= (√7-2+√7+2)/2= 2√7/2= √7

x2= (√7-2-√7-2)/2= -4/2= -2