2. a. (7/4+2/8)*1/2=2/2=1
b. (6/9+12/10)*1/2=(2/3+6/5)*1/2=28/15*1/2=14/15
3. ((11/24*2+4/25*5))/(2+5)=(11/12+4/5)/7=(55+48)/60*1/7=103/420
4. 5x-3=x+1/3
4x=10/3
12x=10
x=10/12=5/6
5.2/9*x=4
x=4*9/2=18
6. 4x/5=15/10*(15/90*x*1/5+10/9)
4x/5=3/2*(1/30*x+10/9)
4x/5=1/20*x+5/3
48x=3x+100
45x=100
x=100/45=20/9