Solve the Equation: Finding the Missing Factor in (-3)⬜ = -15

Question

Fill in the missing number:

$(-3)\cdot⬜=-15$

00:07 Let's start by finding the unknown number.

00:15 Remember, a negative times a positive always gives us a negative.

00:19 So, the unknown number must be positive.

00:23 Let's work together to discover what this unknown number is.

00:34 And there you have it! That's how we solve this problem.

Let's remember the rule:

$(-x)\times(+x)=-x$

Let's think about what number we need to multiply by 3 to get 15:

$3\times5=15$

Now let's put the numbers together with the appropriate sign as written in the rule above as follows:

$-3\times(+5)=-15$

$5$