The answer is 3.00-0.22=2.78
Well I don't know !
Let's check out the choices:
A). 3a - 4b = 21, a=0, b=7
3(0) - 4(7) = 21
0 - 28 = 21 Nope. That's not true.
B). 3a - 4b = 21, a=-3, b=2
3(-3) - 4(-2) = 21
-9 + 8 = 21
-1 = 21 Nope. That's not right.
C). 3a - 4b = 21, a=-2, b=-3
3(-2) - 4(-3) = 21
-6 + 12 = 21
6 = 21 Nope. That's not it.
Only one choice left.
This one had better be it:
D). 3a - 4b = 21, a=7, b=0
3(7) - 4(0) = 21
21 - 0 = 21
21 = 21 Yay ! That's it !
If both C and D equal 15 then the answer is 105.
Answer:
C
Step-by-step explanation:
I did the test
x=2
y=-2
you can get x by itself and then plug what x equals into the second equation to figure out what y equals then plug it back into the first equation.