Answer:
The constant of proportionality k is given by k=y/x where y and x are two quantities that are directly proportional to each other. Once you know the constant of proportionality you can find an equation representing the directly proportional relationship between x and y, namely y=kx, with your specific k.
2 sticks of butter
5-1=4
4/2=2
She already makes 1 cake so we can subtract 5-1
2 cakes can be made per stick of butter so we do 4/2 which is 2
First angle= x+10
Second angle = x
Third angle = x+x+10 or 2x+10
X+10+x+2x +10=180
4x+20=180
Subtract 20 from both sides
4x=160
Divide both sides by 4
X=40
First angle =50
Second angle=40
Third angle =90