Question 268763
let cost of pencil be x
let cost of pen be y

2x+3y=78-------------1
3x+2y=72-------------2

multiply eq1 by 3 & eq 2 by 2

6x+9y=234
6x+4y=144

solve for y by subtracting the equations

5y=90
y=90/5=18

substitute the value of y in eq1

2x+3*18=78

2x=78-54
2x=24
x= 12

pencil costs 12 cents and pen costs 18 cents