Answer:
18
Step-by-step explanation:
12 and 15 are both dividable by 3 and 3 apart so if you subtract 21 by 3 than you get 18
X-intercept is 0
Y-intercept is —4
Umm, since x is -3 (given), your answer should be B, since B is the only one with -3 as an x
hope this helps
