5x+3y/2(x+y)-7x+4y/3(x+y)

1) 5x+3y-2x-9y=3x-6y=3(x-2y) 2) 2*(3a-4)+5=6a-8+5=6a-3=3(2a-3) 3) 15a-(a+3)+(2a-1)=15a-a-3+2a-1=16a-4=4(4a-1)