Explanation:
we have 2 variables :
x = cost per pound of belly beans
y = cost per pound of almonds
to find the solution of 2 variables, we need 2 equations with these variables.
luckily we got them via the 2 given examples :
3x + 5y = $25
12x + 2y = $37
the best to solve this is via elimination. that means we multiply both equations with fitting factors and then add the results, so that one of the 2 variables is not showing in the result, and we can solve for the remaining variable.
with that result we go into one of the original equations and solve for the second variable.
I suggest we multiply the first equation by -4, and the second one just by 1. and then we get
-12x - 20y = -100
12x + 2y = 37
--------------------------
0 -18y = - 63
y = -63/-18 = $3.50
let's use the second original equation (seems to have the nicest factor numbers) :
12x + 2×3.5 = 37
12x + 7 = 37
12x = 30
x = 30/12 = 5/2 = $2.50
1 pound of jelly beans costs $2.50.
1 pound of almonds costs $3.50.