Question

Jack is collecting sea shells from the beach. He begins with 5 pieces in his collection and adds 4 new pieces per day. How many days it will take Jack to have 33 pieces of sea shell in his collection?
days

Answer 1

Jack begins with 5 pieces of sea shell.
He adds 4 new pieces per day.

Let, the required number of days be $x,$ then he will have 33 pieces of total sea shell in his collection.
$\Rightarrow 5+4x=33$

Isolate the variable $x$ and solve the equation.
To isolate the variable, we need to perform some operations that two operations undo each other.
$\Rightarrow$ Addition and subtraction undoes each other
$\Rightarrow$ Multiplication and division undoes each other

In the given equation, 5 is added on left hand side of the equation. So we need to undo the addition operation by subtracting 5 to both sides of the equation.
$\Rightarrow 5+4x=33$
$-5=-5$
$--------$
$4x=33-5$
$\Rightarrow 4x=28$

In the given equation, 4 is multiplied on left hand side of the equation. So we need to undo the multiplication operation by dividing 4 on both sides of the equation.
$\Rightarrow \frac{4x}{4}=\frac{28}{4}\Rightarrow x=7$

Hence, the required number of days is $7.$