9(2w−y)=21w−9y
First you multiply the numbers in the parenthesis by 9
[tex]18w-9y=21w-9y[/tex]
subtract. 21w-18w=3w
[tex]-9y=3w-9y[/tex]
add. -9y+9y=0
[tex]0=3w[/tex]
divide.
[tex]0=w[/tex]
Final answer is 0.
