The sum of two numbers will be zero when you have the same number and one is positive and one is negative. For example 1 + -1= 0
7^4 or seven to the fourth power because 7 is being multiplied by 7 when you raise it to a power.
Answer:
Step-by-step explanation:
Use the Quadratic Formula.
-x² - 4x + 16 = 0
x = [4±√(4²-4(-1)(16)]/[2(-1)] = [4±√80]/(-2) = [4±4√5]/(-2) = -2±2√5
X^2=256
x=±√256
x=±16
x=-16 and 16
