Respuesta :

Answer:

Step-by-step explanation:

Expression: -5 - 4 = -5 + (-4) (subtracting 4 is the same as adding -4) = -9

Expression: 6 - (-2) = 6 + 2 (subtracting -2 is the same as adding 2)

= 8

Expression: (-3)(-7) = -21 (multiplying two negatives gives a positive)