Answer:
10.7 m
Step-by-step explanation:
Given that,
The speed of a sound wave, v = 6,420 m/s
The frequency of the wave, f = 600 Hz
We need to find the wavelength of the wave. We can find it using the below relation as follows :

So, the wavelength of the sound wave is equal to 10.7 m.
Answer:
The last one.
Step-by-step explanation:
X=numbers of hammers
y=numbers of scewdrivers
f(x,y)= total cost in $
f(x,y)=11x+6.65y
f(4,7)=4(11)+6.65(7)=44+46.55=90.55
Sol: an expresion for the total cost of the tools is f(x,y)=11x+6.65 y;
x=number of hammers
y= number of scewdrivers.
The total cost is $90.55
The answer is -3 because - and - are together plus