ANSWER:

d = 15

The swimmer swam 48 kilometres in 15 days.

STEP-BY-STEP EXPLANATION:

Let d = total no. of days the swimmer swam

Total no. of kilometres swam = 48

Average no. of kilometres swam daily = 3.2

THEREFORE:

3.2d = 48

d = 48 / 3.2

d = 15

4 0

3 years ago

Help me out please, im only typing this much because its making me...

Genrish500 [490]

Answer:

B. $x^{2} +2x-8$

Step-by-step explanation:

Here the best method to solve is by substituting the end values of the set in each option , otherwise it will a time consuming problem.

Now substitute x=-4 in all the options

A. $x^{2} -2x-8$

16+8-8=16>0

so out of option A and C option C is correct.

B. $x^{2} +2x-8$

16-8-8=0 which means for the values of x>-4 $x^{2} +2x-8$ is less than 0

Now substitute x=2 in all the options

A. $x^{2} -2x-8$

4-4-8=-8<0 . so option A and C both are incorrect.

B. $x^{2} +2x-8$

4+4-8=0 which means for the values of x<2 $x^{2} +2x-8$ is less than 0

Therefore the correct option is B

6 0

3 years ago