The zeros of the expression j2 - 4j-21 are the solutions of the equation
j²-4j-21.
j² - 4j-21 = 0
(+3_) (+5) = 0
j+ 3 = or j+ = -3
Set the expression equal to 0.
Write the equation in factored form
Use Zero Product Property.
j=7 or j = N
Solve.
The zeros of the expression j2 - 4j - 21 are 2 and .
