solve and graph

Question

I submitted the following but people were not reading the negative sign before the -9, so here it is 6-(-9f)<-3. I don't know if I make the -9f positive since there is a negative sign in front or what to do first. Thank you

Answer 1

6 - (-9f) < -3

 

Yes, the -(-9f) becomes a +9f:

 

6 + 9f < -3

 

9f < -9         [Subtracted 6 from both sides]

 

f < -1          [Divided both sides by 9]

 

Check:

 

f=-1:  6-(-9(-1)) = 6-(9) = -3, which is equal to but not less than -3 as expected (since f ≥ -1)

 

f=-2:  6-(-9(-2)) = 6-18 = -12 which is less than -3 as expected (since f < -1)

 

f=0:  6-(-9(0)) = 6-0 = 6  which is > -3 as expected (since f > -1)

 

Graph:

   -3    -2   -1   0  1   2

<=|==|==o--|--|--|->