Answered

Makahanap ng mga solusyon sa iyong mga problema sa tulong ng mga eksperto ng IDNStudy.com. Ang aming mga eksperto ay nagbibigay ng mabilis at eksaktong sagot upang tulungan kang maunawaan at malutas ang anumang problema.

in a bookstore, pencils and pens cost ddifferent amounts.two pencils and 3 pens cost 50pesos.the total cost of 3 pencils and and 2 pens is 45 pesos. what is the cost of 1 pencil?

Sagot :

Shinalcantaraidn
let 'x' be the cost of 1 pencil
let 'y' be the cost of 1 pen
-------------
two pencils & 3 pens is 50
2x + 3y = 50 -equation 1
3 pencils & 2pens is 45
3x + 2y = 45 -equation 2
---------------
multiply equation 1 with 2 and equation 2 with 3
(2x + 3y = 50) × 2
4x + 6y = 100 -equation 1'
(3x + 2y = 45) × 3
9x + 6y = 135 -equation 2'
------------
subtract equation 1 from equation 2
9x + 6y = 135
- 4x + 6y = 100
5x = 35
x = 7
therefore one pencil costs 7 pesos
NOTE: There's no need to get the value of y since you are only asked of the cost of 1 pencil which is x