Rosmah has $x in her purse. She bougth a book for $10 and spent the rest of her money on 4 pencils. a. Find the price of 1 pencil in terms of x. b. If Rosmah ha

Total money = $x
1 Book = $10

a) Price of 1 pencil
Rosmah spent the rest of money after buying book to buy 4 pencils:
Price of 4 pencils = $x - $10
Price of 1 pencil = ($x - $10) ÷ 4
                           = $[tex] \frac{1}{4} [/tex] x - $2.5
                           = $([tex] \frac{1}{4} [/tex] x - 2.5)

b)Price of 1 pencil, if Rosmah had $30
$x = $30, then x = 30
Price of 1 pencil in terms of x:
$([tex] \frac{1}{4} [/tex]x - 2.5)
= $([tex] \frac{1}{4}\times 30-2.5 [/tex])
= $(7.5 - 2.5)
= $5