Question

Solve no. 8 and no.9

Answer 1

8. 1.5

9 (a) $90

(b) $510

Explanation:

8.

`(1)/(4) - (2x-7)/(8) = \frac {x}{2}`

Multiply all by 8

`2 - (2x-7) = 4x\\2 - 2x + 7 = 4x\\9 = 4x + 2x\\9 = 6x\\(9)/(6) = x\\1.5 = x`

9. (a)

x = cost of one DVD

Since, a blue-ray disc is equal to 2 DVD minus by 10 dollar, then a blue-ray disc = (2x-$10)

$ 610 = 3x + 2(2x - $10)

$ 610 = 3x + 4x - $ 20

$ 610 + $ 20 = 7x

$ 630 = 7x

Divide both side by 7

x = $ 90

Thus, one DVD cost $ 90.

(b)

Blue-ray disc cost = (2x - $10)

3 Blue-ray disc cost = 3(2x - $10)

= 6x - $30

Replace x with $90, since x = $90

= 6 ($90) - $30

= $ 540 - $30

= $510