Question

For her parents' anniversary party, Ellie is considering using one of two venues. A hotel in

Answer 1

The hotel is $250 plus $25 per person so the equation would be

y= 25x + 250

(Y is the total cost and x is the number of people)

the restaurant is $100 plus $40 per person so the equation would be

y = 40x + 100

What we want to know is which x value would make the y values equal to each other. So you can just replace the "y" in one equation with the other equation:

25x + 250 = 40x + 100

and then solve...

1. subtract 100 from both sides

    25x + 150 = 40x

2. subtract 25x from both sides

    150 = 15 x

3. divide both sides by 15

    10 = x

you can check by plugging 10 into the original equations

25(10) + 250

250 + 250 = 500

and

40(10) + 100

400 + 100 = 500

they both cost $500 when you invite 10 people