Answer: 7
Step-by-step explanation:
7
Answer:
3.
3(n + 4) = 21
3n + 12 = 21
3n = 21 - 12 = 9
n = 3.
Answer: C.V=C1.V1 +C2.V2
Step-by-step explanation: C=(C1V1 + C2V2)/V -> C=(20%.V+25%V)/2V-> C=22,5%