the answers for the number 4 are
8,12
and the answers for 7 are
14,21
Answer:
Taking that you didn't provide any other information about the values of x..
The only plausible answer, which probably isn't your case but still can be valid out of context is 19.
Step-by-step explanation:
"X" is 10 in Roman numbers.
9 + 10 = 19
(But I suppose that you had more details to the question that you didn't yet share :) )
OR.. the answer might be an algebraic expression..
<u><em>"9+x" years old.</em></u>
Perimeter = Side + Side + Side
Side 1 = x
Side 2 = x + 7
Side 3 = 2x-7
Plug into the equation:
84 = x + (x + 7) + (2x-7)
84 = x + x + 7 + 2x - 7
Combine like terms:
84 = 4x
Divide by 4 and solve for x:
21 = x
Side 1 = 21
Side 2 = 28
21+7=28
Side 3 = 35
21(2) - 7 = 42 - 7 = 35