Answer:
Daniel (now) is 3 years old, (2 years ago) is 1 year old.
Kevin (now) is 6 years old, (2 years ago) is 4 years old.
Step-by-step explanation:
Now:
-Kevin: k = d + 3
-Daniel: d
2 years ago:
-Kevin: k - 2 = 4(d - 2)
-Daniel: d - 2
We have the equation:
(k - 2) + 2 = k
4(d - 2) + 2 = d + 3
4d - 8 + 2 = d + 3
3d - 6 = 3
3d = 9
d = 3
k = d + 3 = 3 + 3 = 6
[x] represents floor function also called as Greatest integer function.
Floor function is the function that takes as input a real number and gives as output the greatest integer less than or equal to.
like [1.5]=1
[0.7]=0
[-0.3]=-1
Now we have to find set of x-values which satisfies equation [x-1]=[x]
Due to -1 in [x-1], it always produces output value one less than value of [x]
for example when x=0.5 then [x]=[0.5]=0, [x-1]=[0.5-1]=[-0.5]=-1
when x=1.5 then [x]=[1.5]=1, [x-1]=[1.5-1]=[0.5]=0
when x=3 then [x]=[3]=3, [x-1]=[3-1]=[2]=2
From above results we can see that there is no value of x which satisfies the given equation [x-1]=[x]
Hence there is NO solution.
