Question

O Numero -3 e a raiz da equacao x2-7x-2c=0.nessas condicoes , determine o valor do coeficiente c?

Answer 1

x²-7x-2c=0

(-3)²-7.(-3)-2c=0

9+21-2c=0
30-2c=0

2c=30

c=30/2

c=15

Answer 2

x²-7x-2c=0

se x=-3

(-3)²-7(-3)-2c=0
9+21-2c=0

30-2c=0
-2c=-30
2c=30
c=30÷2

c=15