Question

qual o resultado de 2x2-7x=15

Answer 1

2*2 - 7x = 15
4 - 7x = 15
7x = 15 - 4
7x = 11
x = 11/7
x = 1.571428

Answer 2

2x²-7x=15
2x²-7x-15=0
∆=b²-4ac
∆=(-7)²-4.2.(-15)
∆=49+120
∆=169
x=-b±√∆/2a
x=-(-7)-13/2.2
x=7-13/4
x=-6/4 (÷2)
x=-3/2
x=-(-7)+13/2.2
x=7+13/4
x=20/4
x=5
S={(-3/2 ; 5)}