Question

23) x (x + 3) - 40 = 0 (R: 5, -8)​

Answer 1

S= { 5, -8}

Explicação passo-a-passo:

x²+3x -40=0

∆= 3² -4.1.(-40)

∆=9 +160

∆=169

x= - 3±√169/2.1

x= - 3±13/2

x1= -3+13/2= 10/2=5

x2= -3-13/2= -16/2= -8