If m(x) = x3 and n(x) = √ 6 + x , find the function value, if possible.
(m – n)(–5)
a. 124
b. –124
c. not a real number
d. –126

The correct answer is option D.  -126  

Step-by-step explanation:

Points to remember

Composite functions

f(x) and g(x) be the functions then,

(f - g)(x) = f(x) - g(x)

To find the value of (m - n)(-5)

Let  m(x) = x³ and n(x) = √ (6 + x)

(m - n)(x) = m(x) - n(x)

 =  x³ - √( 6 + x)

(m - n)(-5) = m(-5) - n(-5)

 =  x³ - √( 6 + x)

 =  (-5)³ - √( 6 + -5)

 = -125 -  √1

 = -125 -1

 = -126

The correct answer is option D.  -126

4sqrt5

step-by-step explanation:

the base has dimensions of 8 x 4, so the diagonal is 64 + 16 square rooted or 4sqrt5.