<h2><u>
k = 35</u></h2>
Let's solve your equation step-by-step.
14=k(0.4)
Step 1: Simplify both sides of the equation.
14=0.4k
Step 2: Flip the equation.
0.4k=14
Step 3: Divide both sides by 0.4.
= 
<h3><u>
k=35</u></h3>
Answer:
Relative frequency
0.214
0.268
0.446
0.071
Total 1
Step-by-step explanation:
The relative frequency is computed by dividing the individual frequencies to the sum of frequencies.
sum of frequencies=12+15+25+4=56
Class Relative Frequency
10-20 12/56=0.214
20-30 15/56=0.268
30-40 25/56=0.446
40-50 4/56=0.071
Total 12/56+15/56+25/56+4/56=56/56=1
B. (k+10f)(k-5f) you can tell in 2 ways. 1. if the second sign is neg then the signs in the factors are going to be one neg and one positive so that knocks out C and D. Then you look at the second term and since the 5 is positive then the 10 has to be positive so you end up with a positive 5kf.
The second way is to FOIL them out. When you check B you get

combine your like terms and you have your original expression of

Hope that helps