The perimeter of a triangle is 20 cm. The lengths of the sides are x, x + 3, and x + 5. What is the length in centimeters of the longest side?

The side of the longest triangle would be 9cm.

First, we need to find x

To do this, we add all 3 sides together to get the perimeter (20) :

x + x + 3 + x + 5 = 20

3x + 8 = 20

We then use this equation to find x :

3x + 8 = 20

(minus 8 on both sides)

3x = 12

(divide by 3 on both sides)

x = 4

Now we have x, we substitute it into the longest side (x + 5)

4 + 5 = 9cm.

the simplified form is

step-by-step explanation:

we want to simplify the expression,

let us change the middle bar to a normal division sign to obtain,

we multiply the first fraction by the reciprocal of the second fraction to obtain,

we factor to obtain,

we cancel the common factors to get,

we simplify to get,

the correct answer is b

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4