Which describes the calculations that could be used to solve this problem?

Tina has 37 oranges to pack into boxes and bags. She has one box that will hold 13 oranges. She will put the rest of the oranges into bags with 4 oranges in each bag.

How many bags of oranges will Tina be able to fill?

A.
Subtract 37 – 13. Then divide the difference by 4.

B.
Add 37 + 13. Then divide the sum by 4.

C.
Add 4 + 13. Then add 37 to the sum.

D.
Subtract 37 – 13. Then multiply the difference by 4.

A.

Subtract 37 – 13. Then divide the difference by 4.

Step-by-step explanation:

After the box:

37 - 13 left

No. of bags:

(37 - 13)/4

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places

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 -