Como simplifica essa expressão: x+6y-7z+2-8x-12y-10z-20:​

-17 z - 6 y - 7 x + -18

Step-by-step explanation:

Simplify the following:

x + 6 y - 7 z + 2 - 8 x - 12 y - 10 z - 20

Hint: | Group like terms in x + 6 y - 7 z + 2 - 8 x - 12 y - 10 z - 20.

Grouping like terms, x + 6 y - 7 z + 2 - 8 x - 12 y - 10 z - 20 = (-7 z - 10 z) + (6 y - 12 y) + (x - 8 x) + (2 - 20):

(-7 z - 10 z) + (6 y - 12 y) + (x - 8 x) + (2 - 20)

Hint: | Combine like terms in -7 z - 10 z.

-7 z - 10 z = -17 z:

-17 z + (6 y - 12 y) + (x - 8 x) + (2 - 20)

Hint: | Combine like terms in 6 y - 12 y.

6 y - 12 y = -6 y:

-17 z + -6 y + (x - 8 x) + (2 - 20)

Hint: | Combine like terms in x - 8 x.

x - 8 x = -7 x:

-17 z - 6 y + -7 x + (2 - 20)

Hint: | Evaluate 2 - 20.

2 - 20 = -18:

-17 z - 6 y - 7 x + -18

4a. is 3 miles every hour

4b. is 1/3 of an hour per mile

step-by-step explanation: