9.
a 4p + 6q= 8
write down the value of 8p + 12q

b) 20q - 5r = 45
write down the value of 4q -r
(1 mark)
c)
answer
(1 mark)
use your answers to parts a) and b) to write an expression using p.q and r with
value of 41
give your answer in its simplest form.

  a) 16

  b) 9

  c) 16p +28q -r

Step-by-step explanation:

a) The desired coefficients are double those given, so we can multiply the given equation by 2 to get ...

  2(4p +6q) = 2(8)

  8p +12q = 16 . . . . the desired value

__

b) The desired coefficients are 1/5 of those given, so we can divide the given equation by 5 to get ...

  (20q -5r)/5 = 45/5

  4q -r = 9 . . . . the desired value

__

c) There are an infinite number of ways the values 16 and 9 can be combined to get 41. One of the simplest is ...

  2×16 + 9 = 41

Substituting the expressions of part (a) and (b), we get ...

  2×(8p +12q) +(4q -r) = 41

  16p +28q -r = 41

Step-by-step explanation:

4p + 6q = 8 multiply by 2

8p + 12q = 16 <==

20q - 5r = 45 divide by 5

4q - r = 9 <===

not sure I understand this one

can it be something as simple as :

(8p + 12q) + (4q - r) + 16 because this equals 41

     16       +       9     + 16      

12 feet because you take 10 feet and multiply by 12 to make it inches then divide that by 15 to find the scale factor and it is 8 so you take 18 and multiple that by 8. You get 144. You then divide that by 12 to convert it back to feet and you get 12 feet.