Explanation:
3
x
+
y
=
2
−
x
−
3
y
=
6
⇒
−
6
−
3
y
=
x
Substitute this equation into the other system wherever you see
x
.
3
(
−
6
−
3
y
)
+
y
=
6
Distribute
3
onto
(
−
6
−
3
y
)
−
18
−
9
y
+
y
=
2
Combine alike terms
−
8
y
=
20
Divide to solve for
y
−
8
y
−
8
=
20
−
8
⇒
y
=
−
20
8
Then solve for
x
using the value of
y
.
−
x
−
60
8
=
6
x
=
−
108
8
y
=
−
20
8
Answer:
x=-39
Step-by-step explanation:
A = L * W
P = 2(L) + 2(W) or P = 2(L + W)
7 * 10 + 7 * 2 = 7(10 + 2) = 7 * 12.....this will get u the area
2 * 7 + 2 * 12 = 2(7 + 12) = 2(19)...this will get u the perimeter
7 + 12....this gets u neither
2(7 + 12).....this will get u perimeter
7 + 12 + 7 + 12......this will also get u perimeter
7 * 12....this will get u area
The formula

, for n=1 becomes

.
Comparing

with

, we see that
P=900, and 1+r=1.185, which means that r=0.185.
r=0.185 can be written as 18.5%, as a percentage.
Answer: 18.5%