A helicopter will cruise at an altitude of 8,000 feet until it lands on the runway 2.5 hours later. If the altitude is a function of the time elapsed since take-off, what is a reasonable range for this function? A. 0<_x <_ 8,000
B. 0<_y<_ 8,000
C. 0<_x<_ 2.5
D. 0<_y<_ 2.5

-232

step-by-step explanation:

c

step-by-step explanation:

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -

it is impossible.