Please helpp middle school math

suppose 4<a<7. find all the possible values of 15-2a

9514 1404 393

  1 < 15 -2a < 7

Step-by-step explanation:

There are a couple of ways you can do this.

1) Put the minimum and maximum values of a into the expression to see what its corresponding values are:

  15-2a for a=4:

     15-2(4) = 7

  15-2a for a=7:

     15-2(7) = 1

Then ...

  1 < 15-2a < 7

__

2) Solve for a in terms of the value of 15-2a, then impose the limits on a.

  x = 15 -2a

  2a = 15 -x

  a = (15 -x)/2

Now, impose the given limits:

  4 < (15 -x)/2 < 7

  8 < 15 -x < 14 . . . multiply by 2

  -7 < -x < -1 . . . . . . subtract 15

  7 > x > 1 . . . . . . . . multiply by -1

  1 < 15-2a < 7 . . . . . use x=15-2a

_____

The vertical extent of the attached graph is the range of possible values of 15-2a. It goes from 1 to 7.

my answer was deleted because it was to vague the answer is 12.76 becuase its in the hundreths place. john