Can anyone solve?

Question

Bri bought 4 jars of jelly and 6 jars of penut butter for 19.32. Adam Bought 3 jars of jelly and 5 jars of peanut butter for 15.67. Find the cost of a jar of Peanut Butter

Answer 1

Let jars of jelly cost: X
Let jars of peanut butter cost: Y

Then: 

4*X + 6*Y = 19.32
3*X + 5*Y = 15.67

Multiply both sides of the top equation by 3, and  the bottom equation by 4.

12*X + 18*Y = 57.96
12*X + 20*Y = 62.68

Subtract the two:

2*Y = 4.72

Divide by 2:

Y = 2.36 (cost of the jar of peanut butter).

Now use either of those equations and plug in Y = 2.36 to solve for X, which gives:

X = 1.29 (cost of the jar of jelly).