9.

(1) A = 4O
(2) 2P = A

Since P = 192, from (2), we get
2(192) = A
=> A = 384

Substituting into (1), we get
(384)/4 = O
=> O = 96

So he bought 384 – 96 = 288 # more apples than oranges.

Q9: the answer is wrong.

Apple = 4 units

Orange = 1 unit

Pears = 4×2 = 8units

8 units = 192

1 unit = 192/8 =24

3 units = 24×3 = 72 more apples

(1) A = 4O
(2) P = 2A  (This should have been the equation… so sorry)

Since P = 192, from (2), we get
192/2 = A
=> A = 96

Substituting into (1), we get
(96)/4 = O
=> O = 24

So he bought 96 – 24 = 72 # more apples than oranges.

11.

(1) A + J = 220

A – 38 = 5 (J – 38)
=> (2) A = 5J – 190 + 38 = 5J – 152

Substituting (2) into (1), we get
5J – 152 + J = 220
6J – 152 = 220
6J = 372
J = 62 #

10.

A + B + C = 2650
A + (A – 76) + (A – 76)/4 = 2650
9/4A – 76 – 76/4 = 2650
9/4A – 95 = 2650
9/4A = 2745
A = 1220
So B has 1220 – 76 = 1144 # stickers

8.
R = 288
3(B + G) = 288
3(57 + G) = 288
171 + 3G = 288
3G = 117
=> G = 39
So Marc has 288-39 = 249 # more red than green marbles.