-a/5-2/3a+7a
=(-1/5-2/3+7)a
=(92/15)a
x-2x+3x
=(1-2+3)x
=2x
(5a+4b)-(3b-6a)
=5a+4b-3b+6a
=11a+b
2(a+b)-3/5(a+b)
=(2-3/5)(a+b)
=(7/5)(a+b)
=(7/5)a+(7/5)b