4a-9b=22
substitute b=-2
4a -9(-2) = 22
4a +18 =22
subtract 18 from each side
4a = 4
divide by 4
a =1
Choice C
Answer:Yes, it is
Step-by-step explanation:
2^2+4(2)-12=0
4+8-12=0
12-12=0
0=0