a) =45a/9=5a
b) =-35ab/35=-ab
c) =(7x9ab)/(-18)=-7a²b/2
d) =2(a+2b)/2=a+2b
e) =[-9(4x-2y)]/9=4x-2y
f) =25a²b/7
g) =[43x5(x+y)]/2=215(x+y)/2
h) =35(a-b)/10:7/10=[35(a-b)/10]x10/7=5(a-b)
i) =25a:(-21a)=-25a/21a=-25/21
j)= 4a/5x7/2x(-16/70)=4a/5x(-8/10)=-16a/20=-4a/5
k) =[-20(a+b)²]/40=-(a+b)²/2
l) =[-2√2(a-b)³]/4√2=-(a+b)³/2
