Tenzin walks in the mountains. Tenzin has a rule to estimate the time it will take her to complete a walk in the mountains. She uses an average speed of 5 km / h for the distance she will walk and then adds on 1 minute for every increase of 10 metres in height. Tenzin plans to walk 12 km in the mountains with an increase of 800 metres in height. Use Tenzin's rule to work out an estimate for the time it will take her to complete this walk. Give your answer in hours and minutes.

the answer is 99.

answer: 89 x 5

step-by-step explanation:

x³ - 13x + 12

step-by-step explanation:

if you are familiar with the distributive property

a(b+c) = a·b + a·c

then you can apply this here with the binomials.

since multiplication over the real numbers is commutative, we can multiply these binomials in any order. suppose we want to focus on the product (x - 1)(x + 4)

using the distributive property, we can distribute (x - 1) into (x+4):

(x - 1)(x + 4) = x(x - 1)+ 4(x - 1)

and then we apply the distributive property again:

  = x² - x + 4x - 4

combining like terms -x and 4x, we get that

  = x² + 3x - 4

hence we have that (x - 1)(x + 4) = x² + 3x - 4. in this original product, this means that

  (x - 1)(x + 4)(x - 3) = (x² + 3x - 4)(x - 3)

now we can take (x - 3) to the front

  = (x - 3)(x² + 3x - 4)

and then distribute (x-3) inside

  = x²(x - 3) + 3x(x - 3) - 4(x - 3)

now distribute again

  = x³ - 3x² + 3x² - 9x - 4x + 12

and combine like terms to get a final answer of

  = x³ - 13x + 12