4. An airplane descends at a rate of 1,400 feet per minute. Once the airplane starts its descent, what will be its change in elevation after 4 minutes?

5600 feet

Step-by-step explanation:

If it is dropping 1400 every minute then to find the elevation at 4 minutes, you have to multiply 1400 with 4.

explanation:

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 -