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:
Therefore, the pairs of twin-prime numbers are (101,103) , (107,109) , (137,139) , (149,151) , (179,181) , (191,193) , (197,199) . So, the correct answer is “ (101,103) , (107,109) , (137,139) , (149,151) , (179,181) , (191,193) , (197,199) ."
Answer:
D
Step-by-step explanation:
Plug (5, 7) & (8, 13) into each equations and see which one of them makes mathematical sense. You'll find out that y=2x-3 is the right answer.
The answer is 154
This is because you add all the sides
33+56+65=154
Answer: 16 different ways
Step-by-step explanation: