after 4 days 88 boats will have passes under the bridge
Let m and j be the current ages of Matthew and Jenny, respectively.
Now, Matthew is 3 times as old as Jenny, so the variables are in the following relation:

In 7 years, both of them will be 7 years older, i.e. their ages will be m+7 and j+7, and Matthew will be twice as old:

Now, remembering that m=3j, we can rewrite the second equation as

So, Jenny is 7 and Matthew is 21 (he's 3 times older).
In fact, in 7 years, they will be 14 and 28, and Matthew will be twice as old.
Answer:
42 and 21 are composite numbers
The answer is <span>a number that can be written as a ratio of two integers.
I hope this helps!</span>
This question wants you to find a common denominator for the fractions.
This means finding the LCM, least common multiple, for 21 and 9.
This can be done by listing the multiples for each number until they meet at a common one.
9:
9
18
27
36
45
54
63
21:
21
42
63
This means the LCM of 21 and 9 is 63.
So the lowest possible common denominator is 63.
21 • 3 = 63
So you have to multiply the numerator of 2/21 by 3 as well.
2 • 3 = 6
2/21 = 6/63
Now do the same for 1/9.
9 • 7 = 63
Multiply the numerator, 1, by 7.
1 • 7 = 7
1/9 = 7/63
So in the first blanks, you would put 6/63 for what 2/21 is equal to and 7/63 for what 1/9 is equal to.
7/63 is greater than 6/63.
7/63 > 6/63
That means 1/9 > 2/21
So 2/21 < 1/9 is the answer to the last blank.
Hope this helps!