Answer:
c = 2 or c = -3/10
Step-by-step explanation:
23. 10c2 - 21c = -4c + 6
10*cc - 21c = -4c + 6
10cc - 21c + 4c - 6 = 0
10cc - 17c - 6 = 0
c = 17/20 + root (17*17 - 4*10 *(-6)) / 20
c = 17/20 + 23/20
c = 2 or c = -6/20 = -3/10
