What is total cost of 0.5 pound of peaches selling for $0.80 per pound and 0.7 pound of oranges selling for $0.90 per pound?

For peaches, $.80/pound so 0.5 is a half of 1 so you divided it to two and you get: $.80:2=$.40

For oranges, $.90/pound so you 0.7 is 7/10 of 1 so you multiply $.90 to 7/10 or times $.90 to 0.7 and you get $.63

When you add the total, you get $.40+$.63 = $1.03

0.5 x 0.80

= 0.4 for 0.5 pounds of peaches

0.7 x 0.90

= 0.63 for 0.7 pounds of oranges