What is the best estimate for each expression?
 
											 
											yo sup??
so
1/8+2/5=5+16/40=21/40=1/2 (approx)
13/14-1/10=130-14/140=116/140=0 (approx)
1/12+1/20=5+3/60=8/60=0.133=0 (approx)
I hope its correct...fingers crossed.
Hope this helps.