3 notebooks and 2 pens cost Php 330 , 2 notebooks and 3 pens cost Php 240 . FIND THE COST OF 1 NOTEBOOK AND 1 PEN

Question

Help my brain blew up

Answer 1

Cost of 1 notebook = n

Cost of 2 notebooks = 2n

Cost of 3 notebooks = 3n

 

Cost of 1 pen = p

Cost of 2 pens = 2p

Cost of 3 pens = 3p

 

Cost of 3 notebbok and 2 pens = 3n+2p = 330 ---1) x 2

Cost of 2 notebbok and 3 pens = 2n+3p = 240----2)  x 3

Multiply 1) by 2 and 2) by 3

6n+4p=660   ----a)

6n+9p=720   ----b)

substracting b) from a)

-5p=-60

p=12 

from 1) 3n+24=330

3n= 306

n=102

Therefor the cost of 1 notebook is 102 and that of 1 pen is 12.

 

Answer 2

duplicate submission...IGNORE!

Answer 3

3n+2p=330

2n+3p=240

double the first equation and triple the second equation.

6n+4p=660

6n+9p=720

Subtact the second one from the first:

-5p=-60

p=12

easy to solve n now, right?

You need to practice substitution and elimination methods.