Question

simplify.
-4i(-5)
write your answer in the form a + bi.

Explanation:

Step1: Multiply the coefficients

We have \(-4i(-5)\). First, multiply the real - number coefficients \(-4\) and \(-5\). Using the rule of multiplication of two negative numbers (\((-a)\times(-b)=ab\) where \(a = 4\) and \(b = 5\)), we get \((-4)\times(-5)=20\). And the imaginary unit \(i\) remains as it is.
So, \(-4i(-5)=20i\). In the form \(a + bi\), \(a = 0\) and \(b = 20\), so it can be written as \(0+20i\).

Answer:

\(0 + 20i\)