Answer:
Answer to part A:
1 notebook = $2.5
1 pen = $1.5
Answer to part B:
= 3 pens.
Step-by-step explanation:
- Here's the simultaneous equation.
4n + 3p = $14.50
5n + 6p = $21.50
- Multiply the numerator by the denominators first number and vice-versa.
5(4n + 3p) = $14.50
4(5n + 6p) =$ 21.50
- Here's what you should get.
20n + 15p = $72.50
20n + 24p = $86
- Eliminate the like numbers by subtracting the denominator from the numerator.
20n - 20n = 0
15p - 24p = -9p
$72.50 - $86 = -$13.5
- Divide the result after the equal sign by the result before the equal sign.
-$13.5 ÷ -9 = $1.5p
- Since we've found the cost of one pen as $1.5, lets substitute any of the first equations to get the cost of one notebook.
4n + 3p = $14.50
4n + 3($1.5) = $14.50
4n + $4.5 = $14.50
4n = $14.50 - $4.5
4n = $10.00
n = $2.5
- Here's the answer to part A:
1 notebook = $2.5
1 pen = $1.5
1 ($1.5) = 3($2.5)
$1.5 + $7.5 = $9.0
$27 ÷ 9 = $3
- Therefore, she'll buy each supply thrice:
3 ( $1.5 + $7.5 ) = 3 ( $9.0 )
( $4.5 + $22.5 ) = ( $27 )
$4.5 + $22.5 = $27
= 3 pens.
