Question

The store has 28 notebooks in packs of 4. Three packs of notebooks are sold. How many notebooks are left?

Answer 1

For this case, the first thing we must do is define variables.

We have then:

x: number of packs of 4

y: number of notebooks

The equation modeling the problem is given by:

$y = 4x$

Three packs of notebooks are sold.

Therefore, for x = 3 we have:

$y = 4 (3)\\y = 12$

As the number of notebooks are 28, then the remaining amount is:

$28-12 = 16$

Answer:

There are 16 notebooks left

Answer 2

7x4=28 7 packs
-3 packs
~~4~~packs
4x4=16 notebooks
FYI:im in 3rd grade