Answer:
Like terms:

1.25x²
-8x²
Step-by-step explanation:
Like terms are terms that have the same variable to the same exponent. In this case, the only like terms are those with the variable 'x' to the exponent of '2', or x². This would include the terms:

1.25x²
-8x²
The term 5yx², also includes x², however, it also includes the variable 'y' which makes it 'unlike' the other terms.
Answer: 15 feet
Step-by-step explanation:
Hi, since the situation forms a right triangle (see attachment) we have to apply the next trigonometric function.
Tan α = opposite side / adjacent side
Where α is the angle of elevation to the sun, , the opposite side (x) is the height of the tree, and the adjacent side is the length of the shadow.
Replacing with the values given:
Tan 31 = x /25
Tan 31 (25) =x
x = 15 feet
Feel free to ask for more if needed or if you did not understand something.
I think the answer would be B. 4 cm