solve for a
a x 25 = ( 7 x 20 ) + ( 7 x 5 )a
multiply it out.
25a=140+35a
subtract 35a from both sides
-10a=140
divide both sides by -10
a x 25 = ( 7 x 20 ) + ( 7 x 5 )a
multiply it out.
25a=140+35a
subtract 35a from both sides
-10a=140
divide both sides by -10