Answer:
$210 and $63
Step-by-step explanation:
21 shirts = $147 and 22 shirts =$154 and 23 shirts = $161
We can see from this sequence that the price goes up by $7 when another shirt is added.
So the price of one shirt = $7
Then the price of 30 shirts:
30×$7 = $210
and
9 shirts:
9×$7 = $63
