Answer:
10. (x-12) > 15
11.  -3n ≤12
12. 400 ≤ 11*h
36.36 hours
13.   500 ≥ 150 + n * 50
14.  275≤ 145 + 80 +c
15.  175≥ 45*n +5n Â
She can only buy 3 tickets  ( no partial tickets)
Step-by-step explanation:
10. Write the inequality correctly: The difference of x and 12 is more than 15 Â
Difference is subtraction  more than  is >
(x-12) > 15
11. Write the inequality correctly: The product of -3 and a number is at most 21.
Product is multiplication and  at most means ≤
-3n ≤12
12. Â Wages = hours worked * rate
  400 = hours * 11
He wants to make at least 400
400 ≤ 11*h
Divide each side by 11
400/11 ≤h
36.36 hours
13. Â Total cost = helmet + number of lessons*rate
     She can spend no more than 500
 500 ≥ 150 + n * 50
14. Â Total cans = cans first week + cans second week + cans third week
We want  275 cans or more
275≤ 145 + 80 +c
15. Â Cost of concert = cost of ticket * number of tickets + fee * number of tickets
It cannot cost more than 175
Â
    175≥ 45*n +5n  (   assuming a service fee per ticket)
Combine like terms
175≥ 45*n +5n
 175≥50n
Divide by 50
175/50 ≥50n/50
3.5 ≥ n
She can only buy 3 tickets  ( no partial tickets)