14x-x-28=167;
13x-28=167;
13x=167+28;
13x=195;
x=195:13;
x=15.
8a+7a+15=420;
15a+15=420;
15a=420-15;
15a=405;
a=405:15;
a=27.
16y-7y+38=3683;
9y+38=3683;
9y=3683-38;
9y=3645;
y=3645:9;
y=405
14x-x-28=167;
13x-28=167;
13x=167+28;
13x=195;
x=195:13;
x=15.
8a+7a+15=420;
15a+15=420;
15a=420-15;
15a=405;
a=405:15;
a=27.
16y-7y+38=3683;
9y+38=3683;
9y=3683-38;
9y=3645;
y=3645:9;
y=405