4x + 25y = $16.71, Kelly
6x + 20y = $21.74, Martin
-12x - 75y = $ -50.13
12x + 20y = $43.48
-55y = - 6.65
y(pencils) = $0.12
4x + 25(0.12) = $16.71
4x + 3 = $16.71
4x = $13.71
x(notenooks) = $3.43
Cost of 1 notebook and 5 pencils
x +5y = Cost
0.12 + 5(3.43) = Cost
COST = $17.27