Question

A triangle has one side that measures 12, another side that measures x, and a third side that measures 4 less than x. The perimeter is 26.

Which equation would we use to find the value of x?



x+x+ 4 + 12 = 26
x+x- 4 + 12 = 26
x+x- 4 = 26
x+x+ 4 = 26

Answer 1

How do you express 4 less than x?

Answer 2

4-x
or x-4

Answer 3

Whatever x is, it's going to be 4 less than that.
That means x - 4

Answer 4

4 - x is x less than 4. There 's a big difference between the two.
You need x - 4.

The other two sides are 12 and x
The perimeter is the sum of the measures of the sides, so you need to add x, x - 4 and 12.

Answer 5

Then you set the sum equal to 26 because that's the perimeter.

Answer 6

Which answer did you get?

Answer 7

x+x-4+12=26

Answer 8

Great.