Question

Medal&Fan
The lengths of the sides of a triangle form three consecutive odd numbers. The perimeter is 21 centimeters. What is the length of the longest side?
Select one:
a. 7 cm
b. 11 cm
c. 9 cm
d. 8 cm

Answer 1

you know what consecutive odd numbers mean ?

Answer 2

noooo

Answer 3

11,13,15 would be consecutive odd numbers, for example

Answer 4

Ok, odd numbers are numbers that are not even (5,7) Consecutive is in a row.

Answer 5

consecutuve mean numbers following each other, like 2,3,4 , 100,101,102
but consecutive odd means none of them are divisible by 2
like 3,5,7,9...

Answer 6

so if the first number is x, the second number is x+2 and the third number is x+4.

The perimeter is the sum of those 3 quantities, and equals 21. Can you write and solve the equation that reflects that?

Answer 7

no im still confused, ehh.

Answer 8

well, do you agree that every other number is odd?

Answer 9

umm sure.c:

Answer 10

The answer is C. 9

Answer 11

how

Answer 12

Okay, so if we let x be the first number, then x+2 is the next number, right?

Answer 13

yeahh

Answer 14

and x+2 + 2 = x+4 is the 3rd number

Answer 15

and if we add the three of them together, they equal the perimeter, which is 21:
\[x+(x+2)+(x+4) = 21\]\[x+x+x + 2 + 4 = 21\]\[3x + 6 = 21\]\[3x+6-6 = 21-6\]\[3x=15\]\[\frac{3x}{3} = \frac{15}{3}\]\[x=5\]Now, \(x\) is the first of the 3 numbers, and we want the 3rd of the 3 numbers. As you may recall, the expression for the third number was \(x+4\), so the third number is \(5+4 = 9\)

Or we could just count off 5, 7, 9...

Answer 16

Checking our answer: 5+7+9 = 21

Answer 17

dangg. i wish math came to me as easy as it comes to you. well thanks so muchh.:)

Answer 18

I've had some practice ;-)

Answer 19

oh I bet.c: