Answer:
x = ±
- 3
Explanation:
I'm assuming you want the solutions to that equation, so here goes! (If not, please comment.)
(x-3)(x+9)=27
Let's FOIL this all out and expand. (Remember: First, Outer, Inner, Last.)
x^2 + 9x - 3x - 27
(first+ inner + outer + last)
x^2 + 9x - 3x - 27 = 27
Combine like terms, and add 27 to both sides.
x^2 + 6x - 27 + 27 = 27 + 27
x^2 + 6x = 54
Let's complete the square, because factoring doesn't work, and because it's good practice.
x^2 + 6x + ___ = 54 + ____
In the blank we will put b/2 ^2 = 6/2 ^2 = 3^2 = 9 to complete the square.
x^2 + 6x + 9 = 54 + 9
Now we've got a perfect square factor:
(x + 3)^2 = 63
sqrt(x+3)^2 = 
x + 3 = ± 
x = ±
- 3
Answer:
20 mph
Step-by-step explanation:
First problem:
The new speed is 26 mph.
The old speed was x.
The new speed is 30% higher than the old speed.
1.3x = 26
x = 20
Answer: 20 mph
Second problem:
A number, perhaps a percent or a fraction, is missing from the problem.
The answers are B) and E)
Answer: D. exponential growth
Step-by-step explanation:
Hence, 5+2+3=10 students play exactly two of these sports.
Answer: 10