Question

thanks but i do need help to solve the third part also, I did get these equations but don't know how to put them together to solve the third.

thanks for helping further!

Answer 1

Write equation 1.
4p + 3g = #1.30

Write equation 2.
2p + 4g = #1.20

Now multiply equation 2 by 2 to give
4p + 8g = #2.40

Now multiply that equation by -1
-4p - 8g = -#2.40
Now add this last equation to equation 1. You see the +4p from equation 1 and the -4p from equation 2 add to zero which leaves just g as an unknown. Solve that for the price of g, put that value back into equation 1 to find the cost of p, THEN you can do part 3.

Answer 2

Sorry bit thick, why do you multiply equation 2 by 2?

Answer 3

You have TWO unknowns, both p and g, You must have two equations. The idea here is to MAKE one equations what it needs to be to zero out one of the unknowns. By multiplying equation 2 by 2, I get 2x2 = 4, then by multiplying by -1, I get -4p and you can see that -4p and +4p (from equation 1) add to zero. And that leaves you with just the one unknown containing g. You COULD have multiplied equation 1 by 4 and equation 2 by 3 which will make the g term 12g and they would have added out BUT it's easier to do just the one.