A triangle has side lengths of (8s + 8) centimeters, (s +9) centimeters, and (8t - 1) centimeters. Which expression represents the perimeter, in centimeters, of
the triangle?

Step-by-step explanation:

(16.2t+3.4u+2.9)cm

Step-by-step explanation:

A triangle is a plane shape that has three sides. The perimeter of a triangle is gotten by taking the sum of all the lengths of the three sides. Let the length of the three sides by s1, s2 and s3, the perimeter of the triangle will be expressed as;

P = s1+s2+s3

Given the side lengths

s1 = (8.1t-6.1)cm

s2 = (8.1t+7.1)cm

s3 = (3.4u+1.9)cm

Perimeter of the triangle = 8.1t-6.1+8.1t+7.1+3.4u+1.9

collect the like terms

P = 8.1t+8.1t+3.4u-6.1+7.1+1.9

P = 16.2t+3.4u+2.9

Hence the expression that represents the perimeter, in centimeters, of the triangle is  (16.2t+3.4u+2.9)cm

12r - 8 - 12

you have to combine like terms. below i have bolded the like terms:

12r - 8 - 12

together it combines to:

12r - 20

hope this !