Answer :
a. 4(8m-7n)+6(3n-4m)= 32m-28n+18n-24m=8m-10n
b. 9(r-s)+5(2r-2s)=9r-9s+10r-10s=19r-19s
c. 12(1-3g)+8(g+f)=12-36g+8g+8f=-28g+8f+12
b. 9(r-s)+5(2r-2s)=9r-9s+10r-10s=19r-19s
c. 12(1-3g)+8(g+f)=12-36g+8g+8f=-28g+8f+12