Well, from the first row to the second you added +7 on both sides. On the other rows you merely did some arithmetic.
Usually one gets from the first line to the last one directly :)
Answer:
y = 47
Step-by-step explanation:
All of the angles in a triangle must add up to 180. The angle marked 3y can help us find the missing angle of the triangle: 180-3y
Then you can make an equation to help solve for y:
50 + (2y-3) + (180-3y) = 180
Combine like terms:
227-y=180
y = 47
Answer: 7
Step-by-step explanation:
Simplify both sides of your equation.
Subtract 4 from both sides.
Multiply both sides by 2(-1).
m = -12
It equals to 3/13
this is easy to solve because the denominator is already the same. all you'll need to do is add the the numerators:
2+1=3
and your answer will be 3/13