Answer:
30
Step-by-step explanation:
Problem = 3x + 21 for x=3
3(3) +21 --- subsitute the three for the x
9 + 21 ---- multiply the 3s together
30 ----- add
Answer:

Step-by-step explanation:



The media is 94.5
Because you first order the number and then you have to add 87 and 100 dividend by 2 =187 over 2= 94.5
Answer:
4
Step-by-step explanation:
I think its 4 because the max DVD's he could have bought if shipping was free was 7 but since shipping is not free,he has to equal the amount so 12.99+9.99= 22.98 and the maximum multiplication by 22.98 with the maximum number as 100 would be 91.92, thats my answer
Answer:
15
Step-by-step explanation: