Comment.
9A
Let's use (a) as an example. What number is in front of the x inside be brackets? If I gave you the choice of 1,2,3,4,5 which number is it out of those 5?
If you chose 5, you have the second best answer. You are reading outside the brackets. Not what we need.
If you choose 1, you are well on your way. There is a 1 beside the x.
Now go to the outside of the brackets. What's in front of the x? 1,2,3,4,5.. There is only one number you can choose. It's a 5. So the result outside the brackets is 5x. How did 1x become 5x? You had to put a 5 on the blank to the left of the brackets..
5(5 + x) = 5x + ___ What goes on the line to the right of 5x? Rule whatever you do to one side of a plus sign inside the brackets, you must do to the other side of the plus sign.
It becomes 5*5
So the blank is filled with 25. And here's the answer.
5(5 + x) = 5x + 25 <<<< answer..
Stop don't do anything more. 5x and 25 are not like terms. They don't mix
9B
Let's make this one brief so that you have something to do. What did you multiply 5 by to get 10? You should answer 2.
2(x + 5) = ___ x + 10
What you do on one side of the plus sign, you must do on the other. So what's in front of the x on the right?
2(x + 5) = 2x + 10 <<<< answer
Answer:
B. There is one real, double root
Step-by-step explanation:
For ax² + bx + c = 0, the discriminant is b² − 4ac.
If the discriminant is positive and a perfect square, there are two real, rational roots.
If the discriminant is positive and not a perfect square, there are two real, irrational roots.
If the discriminant is 0, there is one real, double root.
If the discriminant is negative, there are two complex roots.
Here, a = 64, b = -16, and c = 1.
b² − 4ac
= (-16)² − 4(64)(1)
= 0
The discriminant is 0. Therefore, there is one real, double root
Dr /dt = 7
A = pi r^2
dA / dr = 2pir
dA/dt = dA/dr * dr/dt = 2pir * 7 = 14pir
when r = 12 rate of change of the area = 14*pi*12 = 168pi
= 527.79 cm^2 / minute to nearest hundredth
