25 hope it helps have a great day :)
Answer:
<4= 164
Step-by-step explanation:
the sum of any 2 angles of a triangle is equal to the exterior linear angle of the triangle
<1+<2=<4
8x+9+5x+12=14x+10
13x+21=14x+10
21=x+10
11=x
<4=14x+10
<4=14(11)+10
<4=154+10
<4= 164
The answer to the question
4
x
+
y
−
2
z
=
0
4
x
+
y
-
2
z
=
0
,
2
x
−
3
y
+
3
z
=
9
2
x
-
3
y
+
3
z
=
9
,
−
6
x
−
2
y
+
z
=
0
-
6
x
-
2
y
+
z
=
0
x
+
2
y
=
4
x
+
2
y
=
4
,
2
x
+
4
y
=
8
2
x
+
4
y
=
8
3
x
+
y
=
4
3
x
+
y
=
4
,
6
x
−
7
y
=
2
7n-84 would be your correct answer, 7 times n is 7n. 12 times 7 is 84 so therefore your answer would be 7n-84