Question

-×(ao quadrado)+7×+30=0

Answer 1

-x^2+7x+30=0
A= -1 B=7 C=30
Delta= b^2-4.a.c
Delta= 7^2-4.(-1).30
Delta= 49+120
Delta= 169

X= -b ± √delta : 2.a
X= -7±√169 : 2.(-1)
X= -7±13 : -2
X'= -7+13:2= 6:2=3
X"= -7-13:2= -20:2= -10