Question

What is the perimeter of the triangle?

Answer 1

Given :-

3 sides of a triangle :-

$4 {m}^{3 } \: + 2 {m }^{2} \: - \: m \:$

$7 {m}^{3} \: - 3 {m}^{2} + \: 2m$

$4 {m}^{3} \: + 2 \: {m}^{2} \: - 2m$

Therefore ,

perimeter of triangle is sum of all sides :-

$= (4 {m}^{3} + 2 {m}^{2} - m) + (7 {m}^{3} - 3 {m}^{2} 2m) + (4 {m}^{3} + 2 {m}^{2} - 2m)$

$= 4 {m}^{3} + 7 {m}^{3} + 4 {m}^{3} + 2 {m}^{2} - 3 {m}^{2} + 2 {m}^{2} - m + 2m -2m$

▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂

Hence , your answer is

$\huge\green{15 {m}^{3} + {m}^{2} - m}$

Answer 2

Answer:

D

Step-by-step explanation:

When you add up

$(4m^3+2m^2-m)+(4m^2+2m^2-2m)+(7m^3-3m^2+2m)$,

you have $15m^3+m^2-m$,

which is what D is.

Side note:

You only add up the exponents when you multiply.