A) How high up the wall does it reach?
Use the Pythagorean theorem
Height^2 + Base^2 = Hyp^2
H^2+ 2^2 = 4^2 Subtract the 2^2 from both sides
H^2 = 4^2 -2^2 Multiply the square roots of both the numbers
H^2= 16 - 4
H^2 = 12
H= sqrt(12) m
Hope this helps
Answer:
addition
Step-by-step explanation:
The given expression is 
We want to determine the last operation performed when evaluating this expression for x=3.
We substitute to get:

Multiply within the parenthesis to get:

Subtract to get:

Evaluate the exponent to get:
4+4
Add to obtain:
8
Hence the final operation is addition
5600 is number 23 helps it helps
Let us convert the percentages to decimal format first.. so 5% is just 5/100 or 0.05 and 15% is just 15/100 or 0.15
so hmmm, so, let's say it needs "x" amount and "y" amount of each respectively, so, whatever "x" and "y" are, they must add up to 100, and whatever their concentration is, must add up to what the mixture yields
thus

solve for "x"
what's "y"? well, y = 100 - x