Hey there! :D
Divide 15 by the numerator so we can find 1/7.
15/5= 3
3*7= 21
The number is 21.
I hope this helps!
~kaikers
I worked out the problem hope it helps
1.70 - 0.45 = 1.25
1500 ÷ 1.25 = 1200
Gina must sell 1200 cards before she can make a profit
Divide I from both sides then subtract r from both sides, too so in the end:
R= (E-r)/I