Question

HELP, 30 POINTS !!

A rock collection of 77 rocks is displayed on a set of shelves. Each shelf holds the same number of rocks. The number of rocks on each shelf is more than the number of shelves.

How many shelves are used to display the rocks?

Drag the answers into the box to correctly complete the statements.

Fill in the blank, the choices are below.


The Equation _______, where s is the the number of shelves, can be used to solve this problem. The rock collection is displayed on _______ shelves.


Choices:
• 7
• 11
• 73
• 81
• √73
• √81
• s^2+4=77
• s^2-4=77
• s(s+4)=7
• s(s-4)=7

Answer 1

The first one is S(s-4)=7 , and the Second one is 7

Answer 2

Answer: s(s+4)=7, 7 shelves

Explanation:

I think it's easiest to find these type of answers by finding the common factors of a number. First 77, they are 1×77 & 7×11.so you can have 11 rocks on 7 shelves or 7 rocks on 11 shelves. The question states the number or rocks on the shelf is more than the number of shelves, so you must have 11 rocks on 7 shelves. You know you have 77 rocks, so the equation must equal 77. I plugged 7 in for s in the equations to determine the correct answer. 7(7+4)=77.