I need help with my introductory algebra math homework?

Question

The problem says "You like to drive to a special store to buy your favorite gourmet jelly beans for a low price of $1.30 a pound. However, your best friend points out that you are spending about $3 on gas every time you drive to that store and that you might as well buy your jelly beans at your local supermarket for $2.10 a pound. You decided to show him that you are getting enough jelly beans to make it worth the trip.

The first question (part A) asks me to let X represent the number of pounds of jelly beans and to write an equation to determine the total cost, C, if I buy them at the special store. I wrote:

C=1.30X+3

Then (part B) it asks me to write an equation to determine the total cost, C, if I buy the jelly beans at the local supermarket. I wrote:

C=2.10X

Those are both right

But this is where I get stuck….

It says “The two equations in part A and part B form a system of two linear equations. Solve this system using an algebraic approach.”

I don’t know how to do this!!

Answer 1

Okay, you did this correct. Now just set the two equations to eachother and solve for x.

1.30X+3=2.10X
3=.8x
x=3.75

thus, you need to buy 3.75 lb to break even. More will save money.

Answer 2

C = 1.30x+ 3 eq.(A)
C = 2.10x eq. (B)
2.10x = 1.30x + 3
0.8 x = 3
x = 3/0.8
x = 3.75 pounds of jelly beans at least to get an equal (C) cost.
C= 1.30 (3.75) + 3 = 7.875 @ eq (A), C=2.1(3.75)=7.875 @ eq(B) .... ok? email me if ok, please