Question

Please help with this simultaneous equation you can use any method(Only number 6)

Answer 1

Pencil: $0.60 Rubber: $0.48

Explanation:

Let the cost of a pencil be p and the cost of a rubber be r.

`p+r=1.08` (Equation 1)

`4p=5r` (Equation 2)

Divide both sides by 4:

`p=(5)/(4) r`

Substitute this into Equation 1:

`(5)/(4) r+r=1.08`

Multiply both sides by 4:

`(5)/(4)r* \:4+r* \:4=1.08*4`

`5r+4r=4.32`

`9r=4.32`

Divide both sides by 9:

`(9r)/(9)=(4.32)/(9)`

`r=0.48`

Since r + p = 1.08,

`p=1.08=0.48=0.60`