The cost of three notebooks and four pencils is $8.50. The cost of five notebooks and eight pencils is $14.5". Determine the cost of one notebook and the cost of one pencil. (Needs an algebraic solution)

Question

anonymous · Answer

$14.50*

anonymous · Answer

lets call x notebooks and y pencils

anonymous · Answer

$$3N +4P = 8.50$$$$5N + 8P = 14.50$$Multiply the top equation by -2.  $$-6N - 8P = -17$$ use elimination to solve.
-6N-8P = -17
 5N +8P = 14.50
Result: -N = -2.50
N(otebook) = 2.50

Plug in N to either equation.
3(2.50) +4p = 8.50
4P + 7.5 = 8.50
4P = 1
P = .25

anonymous · Answer

Okay

anonymous · Answer

the first equation will then look like
3x + 4y =$8.50