X1+X2=3/2 X1*X2=-5/2(1) 1/X1+1/X2=(X1+X2)/X1*X2=-3/5(2) x1²+x2²=(X1+X2)²-2*X1*X2=29/4(3) |x1-x2|=√（X1-X2)²=√(X1+X2)²-4*X1*X2=49/4
