faapfyu 1) (-4/5-7/10)/1/2+3=(-8/10-7/10)/1/2+3=-15/10*2/1+3=-15/5*1/1+3=3-3=0

2) 2^2b^7*25(a^2b)^3*4a^2=2a^2b^7*25a^6b^3*4a^2=50a^8b^10*4a^2=200a^10b^10