Answer:
hello hello hello is there anybody in there
Step-by-step explanation:
The string would have to be 4 feet long to have a frequency of 400cps because each foot=100cps
Given is a piecewise function which follows different expressions according the the value of input x.
Given 
It says to find f(-4) i.e. the value of function f(x) at x = -4.
At point x = -4, f(x) is x³, if -5 ≤ x ≤ 2.
So, f(-4) = (-4)³
f(-4) = -4 × -4 × -4
f(-4) = -64.
Hence, option A is correct i.e. -64.
1/2x + 42 = 4x
-1/2x -1/2x
------------------------
42 = 3.5x
/3.5 /3.5
------------------------
12 = x
the number is 12
explanation: 42 more than 1/2 of a number can be written as 1/2x + 42
four times a number can be written as 4x.
42 more than 1/2 of a number is equal to 4 times a number. So 1/2x + 42 = 4x.
Hope this helps :)