The cost of three notebooks and four pencils is $8.50. The cost of five notebooks and eight pencils is 14.50. Determine the cost of one notebook and the cost of one pencil.

Question

skullpatrol · Answer

Any ideas?

skullpatrol · Answer

Step 1 Read the problem carefully.Decide what unknowns are asked for?

anonymous · Answer

let notebooks be x and pencils be y

anonymous · Answer

so 3x+4y = £8.50
5x+8y= £14.50

anonymous · Answer

1. 3x+4y =8.50
2. 5x+8y =14.50

times eq1 by 2 
1. 6x+8y=17
now minus eq2 form eq1 
6x - 5x = x 
8y- 8y= 0 
17- 14.50 = 2.50 
sox=2.50

anonymous · Answer

now subsitute x into eq2 
5x+8y=14.50
5*2.50 = 12.50
12.50 +8y = 14.50 
take away 12.50 from both sides 
8y = 2 
divide both sides by 8 
y = 2/8 or 0.25 or 25 pence

anonymous · Answer

@skullpatrol they are asking for how much 1 notebook and pencil would cost