Answer:
5 (x-y)=15
2x-2y=6 and
y-x=-3
Step-by-step explanation:
first x-y=3, so you substitute x by y or y by X. anyway I substituted x by y. so x=y+3.
a. 5(x-y)
5[(y+3)-y] (first you substitute x by y+3.)
5 [y+3-y] ( then you remove the bracket.)
5[y-y+3] ( you collect like terms in the bracket.)
5 [3] (-y+y=0) so it means 5×3=15.
b. 2x-2y (like before you substitute x by y+3.)
2 (y+3)-2y
2y+6-2y (then you remove the bracket.)
2y-2y+6 (you collect like terms)
0+6=6. (because 2y-2y=0)
c. y-x
y-(y+3) ( you substitute x by y+3.)
y-y-3 (you remove the bracket)
0-3=-3 (because y-y=0)
