Question

3 pizza and 4 sandwiches cost $34. 3 pizza and 7 sandwiches cost $41.50. How much does a pizza cost?

Answer 1

3p+4s=34
3p+7s=41.5
Do I substitute?

Answer 2

You can but this problem lends itself well to elimination if you multiply one of the equations by -1

Answer 3

Okay thank you.

Answer 4

I cqn also add them correct?

Answer 5

right

Answer 6

but how would I do that?
Just regularily add? Or...

Answer 7

Yes. you'd have add the like terms and the p's would cancel

Answer 8

-3p-4s=-34
3p+7s=41.5
______________
3s = 7.5

Answer 9

so...6P+11s=75.5

Answer 10

You have to multiply one of them by -1 before adding them together.

Answer 11

okay... in that case...

Answer 12

-3p-7s=-41.5? Multiply all?

Answer 13

-7.5

Answer 14

Yes you multiply all of them

Answer 15

You got -3s = -7.5?

Answer 16

mhmm.

Answer 17

39+30/12=34..

Answer 18

and from here you can solve for s

Answer 19

5/2

Answer 20

So...

Answer 21

17-5/2...right?

Answer 22

i think...

Answer 23

basically...

Answer 24

wait wait wait..being a dumbcluck here.

Answer 25

34/2 is...um...

Answer 26

36/2!...

Answer 27

... ><''

Answer 28

The 5/2 is right.

Answer 29

3p+7(5/2)=41.5

Answer 30

We just substitute from there?

Answer 31

right

Answer 32

3p+35/2=41.5 So what do I do then?

Answer 33

solve for p.
3p = 41 - 35/2

Answer 34

3p = 24

Answer 35

okay..thanks.