Ahmed is taking orders for lunch. A slice of pizza cost $2.9 and a chicken sandwich costs $3.9. He collects $25.3 for the group of 7 people.
Let x=number of pizza orders.Let y=number of chicken orders
X+Y=7 2.9X+3.9Y=25.3 Get X by itself: X=7-Y Substitute for X: 2.9(7-Y)+3.9Y=25.3 Time it out: 19.5-2.9Y+3.9Y=25.3 Add the Ys: 19.5+Y=25.3 Subtract from both sides: Y=5 So, X is equal to two orders, and Y is five.
