Question

At an Italian bistro, the cost of 2 plates of spaghetti and 1 salad is $27.50. The cost for 4 plates of spaghetti and 3 salads is $59.50. Write and solve a system of equations to find the cost of 1 plate of spaghetti and 1 salad.

Answer 1

2a+1b=27.50
4a+2b=59.50
Multiply first equation by -4 and the second by 2 so you can drop off the a values then add the equations together.  Then solve for b.  You should get b=6.

Then plug b into one of the original equations and solve for a and you should get 10.75

So a plate of spaghetti is $10.75 and a salad is $6.