Answer:
-4 and 4
Step-by-step explanation:
<u>Method 1</u>
Apply Difference of Two Squares Formula: 
Given 
Rewrite 16 as 4²
Therefore,
and 






<u>Method 2</u>
Given equation:

Add 16 to both sides:


Square root both sides:


Therefore, x = -4, x = 4
Answer:
~820.8$
Step-by-step explanation:
The total money (M) after 18 years could be calculated by:
M = principal x (1 + rate)^time
with
principal = 400$
rate = 4% compounded monthly = 0.04/12
time = 18 years = 18 x 12 = 216 months (because of compounded monthly rate)
=> M = 400 x (1 + 0.04/12)^216 = ~820.8$
Answer:
Step-by-step explanation:
y = -4x^2 + 4x + 6
Factor out the leading coefficient:
y = -4(x^2 - x) + 6
Complete the square:
y = -4(x^2 - x + (½)^2) + 4(½)^2 + 6
= -4(x-½)^2 + 7