What is the answer to
2/5 =2/10+k

2/5 = 2/10 + k
multiply both sides (each term) by 10, we get
10×2/5 = 10× 2/10 + k ×10
4 = 2 + 10k
OR 10k = 4 - 2
10 k = 2
k = 2 / 10
Or k = 1/5

K=1/5=0.200
rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation.
2/5-(2/10+k)=0

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!