Answer:
1= -4a+7b
2=(7x-5)/3
Step-by-step explanation:
1,
a+3b-(5a-4b)
expand bracket 1st according to BIDMAS
a+3b-5a+4b
collect like terms
a-5a+3b+4b
ans=-4a+7b
2,
X/3+2x-5/3
solve for the 1st two
X/3 +2x
LCM =3 so,
(x+6x)/3=7x/3
use this and solve the last part
(7x/3)-(5/3)
LCM=3
ans=(7x-5)/3