Question

What is the perimeter of the triangle?

Answer 1

D

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.

Answer 2

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`

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Hence , your answer is

`\huge\green{15 {m}^(3) + {m}^(2) - m}`