Kathy stood on the middle rung of a ladder. she climbed up 4 rungs, moved down 3 rungs, and then climbed up 9 rungs. then she climbed up the remaining 3 rungs to the top of the ladder. how many rungs are there in the whole ladder?

Kathy stood on the middle rung of a ladder There are 20 rungs in the ladder.

Solution:

Let there be ‘x’ rungs in the ladder.

It is given that in the beginning she is standing in the middle of the rung. Let the middle rung be  

Now it is given that She climbed up 4 rungs which means she climbed rungs.

Again it is given that she moved down 3 rungs which means she moved down   rungs.

Then she moved down rungs

Again she climbed 9 rungs up and reaches the top which means she climbed rungs

Now we can use the following equation to find the number of rungs in the ladder

x+20 = 2x

20 = 2x-x

x = 20

Thus the number of rungs in the ladder is 20

-13

step-by-step explanation:

f(x)=2x-5 for f(-4)

f(-4)   means let x=-4

f(-4) = 2(-4) -5

f(-4) =-8-5

      = -13