Answer:
Step-by-step explanation:
x-y=7
-3x+9y=-39
Divide the second equation by 3
-x +3y = -13
Add this to the first equation
x-y=7
-x +3y = -13
----------------------
0x +2y = -6
Divide by 2
2y/2 = -6/2
y = -3
Now find x
x-y = 7
x -(-3) = 7
x+3 = 7
Subtract 3 from each side
x = 4
(4,-3)
Or by substitution
x-y=7
solve for x
x = 7+y
-3x+9y=-39
Substitute y+7 in for x
-3(7+y) +9y = -39
Distribute
-21 -3y +9y = -39
Combine like terms
-21 +6y = -39
Add 21 to each side
6y = -18
Since all angles in a triangle are equal to 180 and you already have two angles you just have to subtract.
So, 180-(65 + 45)
Simplify = 180- 110
Equals = 70
A) 35 B) 50. C) 85. D) 30
Do want me to explain it too?
Answer:
C
Step-by-step explanation:
Isometry only includes, rotation, translation, and reflection.
