Answer:

Step-by-step explanation:
Foil the equation!
1. You see that is to the second power so it means this 
2. Then you use the Foil method. First, Outside, Inside, and Last.
3. Combined like terms
4. Answer!
A tip you can use to avoid Foil is this mental math trick: (Keep in mind this only works if the polynomial is being squared.)
1. Multiply the first number by itself = 
2. Add the first number by itself = 
3. Multiply the last number by itself = 
4. Combined to form your answer = 
NOTE: This is the same thing as a foil but it uses mental math so it takes less time!
Answer:
12
Step-by-step explanation:
radius is half of diameter
The image I included should help you solve the problem
Answer: 30
Step-by-step explanation: Formula for Area of a triangle = 1/2 Base * Height. 12*5 = 60; 60/2 = 30.
Step-by-step explanation:
Root of the function, where y = 0
f(x) = x² + 2x - 1
0 = x² + 2x - 1
x² + 2x - 1 = 0
x² + 2x = 1
x² + 2x + 1 = 1 + 1
(x + 1)² = 2
x + 1 = ±√2
x = -1 ± √2
Roots → x = -1 ± √2