Question

Podem me dizer quanto dar essas expressões em Z?

a)23-(-5+10)-(-2-7)+(+8+5)-12

b)-(-15)+(-8-12)-(-13)-25

c)-30+(-21+17)-(17-19)-(-24)

d)-(-8)+(+21)-(-20)-(-8+30)

Answer 1

a) 23-(-5+10)-(-2-7)+(+8+5)-12=
23+5-10+2+7+8+5-12=
28-10+2+7+8+5-12=
18+2+7+8+5-12=
40-12=
28

b)-(-15)+(-8-12)-(-13)-25=
+15-8-12+13-25=
+7-12+13-25=
-5+13-25=
+8-25=
-17

c)-30+(-21+17)-(17-19)-(-24)=
-30-21+17-17+19+24=
-51+17-17+19+24=0
-51+19+24=0
-32+24=0
-8

d)-(-8)+(+21)-(-20)-(-8+30)=
8+21+20+8-30=
57-30=
27