Answer:
C. a = 7
D. c = -3
Step-by-step explanation:
C. 7(2a + 3) + 21 = 100+ 40
14a + 21 + 21 = 140
14a = 140 - 21 - 21
14a = 98
a = 7
D. 6+ 14 - 12c = 56
20 - 12c = 56
-12c = 56 - 20
-12c = 36
c = - 3
c.7(2a+3)+21=100+40
14a+21+21=140
14a+42=140
14a=140-42
a=98/14
a=7
d.6+14-12c=56
20-12c=56
-12c=56-20
c=36/-12
c=-3
