Answer:
Look at the equations:
y
=
−
9
x
−
21
and
y
=
5
x
+
7
Because both equations equal (y), they both equal the same.
If an equations says "
y
=
−
9
x
−
21
" , that means we can replace (y) with
−
9
x
−
21
.
Therefore when i take the equation:
y
=
5
x
+
7
, we can replace (y) to get:
−
9
x
−
21
=
5
x
+
7
Now isolate (x):
−
9
x
−
21
=
5
x
+
7
⇔
−
21
=
14
x
+
7
⇔
−
28
=
14
x
⇔
x
=
−
2
-2.5x is the answer for this question i believe if i did it right'<span />
You combine like terms like 8y+13y which gives you 21y and don't forget the -5x so your simplified equation would end up being A. 21 - 5x
Answer:
D.
Step-by-step explanation:
A=2πrh+2πr2 is the equation, so now all you have to do is plug the numbers in. (also there's a calculator for this on google btw)
