Question

Help solving question two. Please ignore my work. I wasn’t sure how to do it.

Answer 1

SOLUTIONS

Let the cost of one CD be c

Let the cost of one books be b

since Sarah can buy one CD and 2 books for $28

and also 2 CD and 3 books for $48

`\begin{gathered} c+2b=28............(1) \\ 2c+3b=48..........(2) \end{gathered}`

Using substitution method

`\begin{gathered} from\text{ equ\lparen1\rparen} \\ c=28-2b..........(3) \end{gathered}`

sub the value of c in equ(2)

`\begin{gathered} 2c+3b=48 \\ 2(28-2b)+3b=48 \\ 56-4b+3b=48 \\ -b=48-56 \\ -b=-8 \\ b=8 \end{gathered}`

sub the value of b in equ(3)

`\begin{gathered} c=28-2b \\ c=28-2(8) \\ c=28-16 \\ c=12 \end{gathered}`

Therefore the cost of a CD = 12 and the cost of a book = 8