Solve the Multiplication Equation: 10 × ? = -100

Let's remember the law:

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

Let's think about which number we need to multiply by 10 to get 100:

$10\times10=100$

Now let's put the numbers together with the appropriate sign as written in the law above, and we'll get:

$+10\times(-10)=-100$