Please remember that a parallelogram is 4 parallel lines and the opposite sides are congruent. With that information you should be able to pick the correct answer.
first step is to subtract 21 from both sides
2m+21-21=3-21
2m=-18
2m/2 and -18/2
m=-9
So the final answer is m=-9 (negative nine equals m)
It would be 20ft have a great day
4x - 5y = -12
-x + 5y = 18
Add the equations together:
4x + -x = 3x
-5y + 5y = 0
-12 + 18 = 6
So now you have:
3x = 6
Divide both sides by 3:
X = 2
Now you have the value of x, replace x with 2 in one of the equations and solve for y:
4(2) -5y = -12
8 -5y = -12
Subtract 8 from both sides:
-5y = -20
Divide both sides by -5:
Y = 4
The solution is x = 2 and y = 4 which is written as (2,4)
Y=-2 should be the answer