Algebra Puzzle (3 x 4)

First, we take the present as p, drum as d, and the pumpkin as u.
Refer to the third column:

p + p + p = 33

Hence,

p = 33 ÷ 3 = 11

Now we refer to the first row:

70 = p + d + p + d
=11 + 11 + d + d
=22 + d + d

Hence,

70 - 22 = d + d
48 = d + d
d = 48 ÷ 2
d = 24

Finally, we refer to the last column:

66 = d + u + d
66 = 24 + 24 + u

Hence,

66 - 24 - 24 = u
18 = u

So the answer is: Present = 11
Drum = 24
Pumpkin = 18

Algebra Puzzle (3 x 3)

First, we take the ice-cream as c.
The flower as w, and the gear as g.

Therefore,
15 = c + c + c
= 3c
c = 15 ÷ 3
= 5

Now that we know c = 5, the next step(3rd row) is:

35 = c + g + g
= 5 + g + g

Thus,

35 - 5 = g + g
30 = g + g
30 ÷ 2 = g
15 = g

Finally, we can evaluate(the 1st row):

c + w + g
=5 + 15 +w
=20 + w
=23

Therefore,

w = 23 - 20
= 3

So the answer is: Flower = 3
Gear = 15
Ice - cream = 5