Answer:
y=8
Explanation:
the angle that is equal to 10x-3 and the angle that is equal to 7x+45 are equal to each other because they are corresponding angles so we setup an equation which would be
10x-3=7x+45
step 1
add 3 to each side
-3+3 = they cancel out
45+3=48
now we have
10x=7x+48
step 2
subtract each side by 7x
7x-7x cancels out
10x-7x=3x
3x=48
step 3
divide each side by 3
3/3 cancels out
48/3=16
so x =16
now we plug it into to 10x+3
10x16=160 160-3= 157
so the angle that is equal to 157 and the one that is equal to 3-y are supplementary angles so they will add up to equal 180 so to solve y we setup the equation which would be
180=157+3y-1
step 1 combine like terms
157-1=156
180=156+3y
step 2 subtract each side by 156
156-156 cancels out
180-156=24
so now we have
24=3y
next we divide each side by 3
3/3 cancels out
24/3=8
y=8
hope this makes sense :D