Answer:
$28
Step-by-step explanation:
40% of 20 is 8
20 + 8 = 28
Answer:
Simplify the expression: 
Use the exponent power:
Apply the given rules;
Simplify:
then;
Therefore, the simplified expression of is, 
First we want to find how much it costs for 1 stamp, so we do 8.28 divided by 18, which equals 0.46. Then, we multiply 0.46 and 12, which is 5.52. Therefore, it would cost $5.52 to buy 12 stamps.
Answer: There are no real number roots (the two roots are complex or imaginary)
The discriminant D = b^2 - 4ac tells us the nature of the roots for any quadratic in the form ax^2+bx+c = 0
There are three cases
- If D < 0, then there are no real number roots and the roots are complex numbers.
- If D = 0, then we have one real number root. The root is repeated twice so it's considered a double root. This root is rational if a,b,c are rational.
- If D > 0, then we get two different real number roots. Each root is rational if D is a perfect square and a,b,c are rational.
