Question

PLEASE HELP- John and Ariana bought school supplies. John spent $10.60 on 5 notebooks and 5 pens. Ariana spent $7.30 on 3 notebooks and 4 pens. What is the cost of 1 notebook & what is the cost of one pen? PLEASE HELP

Answer 1

Cost of one notebook is 1.40 and one pen is1.40andonepenis0.90

Explanation:

Let,

Notebook = x

Pen = y

According to given statements;

\begin{gathered}Multiplying\ Eqn\ 1\ by\ 4\ and Eqn\ 2\ by\ 5\\4(5x+4y=10.60)\\20x+16y=42.40 \ \ \ Eqn\ 3\\ 5(4x+3y=8.30)\\20x+15y=41.50 \ \ \ Eqn\ 4\\Subtracting\ Eqn\ 4\ from\ Eqn\ 3\\(20x+16y)-(20x+15y)=42.40-41.50\\20x+16y-20x-15y=0.90\\y=0.90\\Putting\ value\ of\ y\ in\ Eqn\ 1\\5x+4(0.90)=10.60\\5x+3.60=10.60\\5x=10.60-3.60\\5x=7\\Dividing\ both\ sides\ by\ 5\\\frac{5x}{5}=\frac{7}{5}\\x=1.40\end{gathered}Multiplying Eqn 1 by 4 andEqn 2 by 54(5x+4y=10.60)20x+16y=42.40 Eqn 35(4x+3y=8.30)20x+15y=41.50 Eqn 4Subtracting Eqn 4 from Eqn 3(20x+16y)−(20x+15y)=42.40−41.5020x+16y−20x−15y=0.90y=0.90Putting value of y in Eqn 15x+4(0.90)=10.605x+3.60=10.605x=10.60−3.605x=7Dividing both sides by 555x=57x=1.40

Cost of one notebook is 1.40 and one pen is1.40andonepenis0.90