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
86 *2 = 172
172/3 = 57.33
54 + 56 +58 =168
168/2 =84
56 + 58 +60 = 174
174/2 =87
58 +60 +62 = 180
180/2 = 90
60 +62 +64 = 186
186/2 = 93
62 +64+66 = 192
192/2 = 96
there are 3 sets of numbers that fall between 84 & 96
1 set equals 84 and 1 set equals 96
so if you are counting those there are 5 sets
Answer: do the a dozen for $13.50
Step-by-step explanation: It will help save money
