In how many ways can 4 books be arranged on a shelf if there are 8 books to choose from?

Mathematics

1 answer:

dsp733 years ago

8 0

Answer:

1680 ways

Step-by-step explanation:

By using the formula for permutation, which is nPr=n!/(n-r)!,

8P4=8!/(8-4)!

=8!/4!

=8×7×6×5

=1680

Or if you just want to use the multiplication rule (which is simpler).

8×7×6×5=1680

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Step-by-step explanation:

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3 years ago

Which graph is the solution to the inequality –3x − 6 > 9?

Sati [7]

Answer:

See attachment

Step-by-step explanation:

First solve this like a normal equation:

-3x - 6 > 9

Add 6 to both sides:

-3x > 9 + 6

-3x > 15

Divide by -3 and remember to switch the inequality sign:

x < 15/(-3)

x < -5

Think about the graph of x = -5. It's a vertical line crossing the y-axis at x = -5. Now, we have x is less than -5. That means all the values less than -5 should be viable solutions. So, shade the part of the graph to the left of the vertical line.

Also, since we have x < -5 and not x ≤ -5, the line should be dotted.

See graph attached.

~ an aesthetics lover