<h2>
The top of the ladder is descending at 0.3 m/s.</h2>
Step-by-step explanation:
By Pythagoras theorem we know that
Hypotenuse² = Base² + Perpendicular²
h² = b² + p²
We have for ladder
h = 5 m
b = 3 m
5² = 3² + p²
p = 4 m

Differentiating h² = b² + p² with respect to time

The top of the ladder is descending at 0.3 m/s.
Answer:
5x³ - 2x²
Step-by-step explanation:
Step 1: Write out expression
4x³ - x² + 4x + x³ - x² - 4x
Step 2: Combine like terms (x³)
5x³ - x² + 4x - x² - 4x
Step 3: Combine like terms (x²)
5x³ - 2x² + 4x - 4x
Step 4: Combine like terms (x)
5x³ - 2x²
Answer:
10
Step-by-step explanation:
f(x) =3x-x=2x,
f(7-2)=f(5)= 2*5=10
Answer:
15
Step-by-step explanation:
To find how many she bought, we have to divide. So we do 105/7=15.