Answer:
To find the value of y, you would put your expressions (12y+3, and 51 equal to each other, because they are both the same length)
12y+3=51
12y=48 (51-3=48)
y=4 (divide both sides by 12, 48/12=4)
Then to find x you want to find the missing degree of the triangle
we already know that one degree is 63 and the other is 56,
A triangle equals 180 degrees
56+63=119
Then you want to subtract 119 from 180 to find out the missing degree
180-119=61
x=61 degrees
y=4 and x=61
Hope this helps ;)
