33. 15x10=150x9
the answer is b
34. a
The scale factor applied to the model is 8000. 8000 times one equals 8000
That's a 33% increase.
I calculated this using the formula:

Where n = the new value (16 in your question), o = the old value (12 in your question) and the result is outputted as a percent increase. You can check that this is correct by finding 33% of 12, adding the result to 12, and checking that the result equals your "new" number.
Note that 33% is only an approximation as your question requires a number rounded to the nearest whole.
Congruent means they are the same size
To prove the two triangles are congruent you would need to know the length of at least two of the sides. If two sides were not known you would need to know the length of one side and at least one of the unknown angles.
(4x + 3y)² =
<span>(4x)² + 2 (4x) (3y) + (3y)² = </span>
<span>16x² + 24xy + 9y²</span>