OK. These problems are easy if you know the quadratic formula,
and they're impossible if you don't.
Here's the quadratic formula:
When the equation is in the form of Ax² + Bx + C = 0
then x = [ -B plus or minus √(B²-4AC) ] / 2A
I'm sure that formula is in your text or your study notes,
right before these questions. You should cut it out or
copy it, and tape it inside the cover of your notebook.
Then, you'll always have it when you need it, until
you have it memorized and can rattle it off.
The first question says 3x² + 5x + 2 = 0
Is this in the form of Ax² + Bx + C = 0 ?
Yes ! A=3 B=5 C=2
so you can use the quadratic formula to solve it.
x = [ -B plus or minus √(B²-4AC) ] / 2A
= [ -5 plus or minus √(5² - 4·3·2) ] / 2·3
= [ -5 plus or minus √(25 - 24) ] / 6
= [ -5 plus or minus √1 ] / 6
x = -4 / 6 = -2/3
and
x = -6 / 6 = -1 .
_______________________________________
The second question says
4x² + 5x - 1 = 0
Is this in the form of Ax² + Bx + C = 0 ?
Yes it is ! A=4 B=5 C= -1
so you can use the quadratic formula to solve it.
x = [ -B plus or minus √(B²-4AC) ] / 2A
Now, you take it from here.
Answer:
khan accademy will help you
Step-by-step explanation:
Answer:
C: p < 0.01
Step-by-step explanation:
We are given;
Spearman rank Correlation Coefficient: rs = 0.53
sample size: n = 13 pairs
Now, from the table attached, tracing n = 13 and locating a corresponding value of rs = 0.53 which falls in between 0.484 and 0.56. Thus, we can see that p is greater than the nominal significance value of 0.05 but less than 0.01.
Thus, correct answer is p < 0.01
4725mi= 24948000ft
There are 5280 feet in every mile!
Answer: B; 2≤x≤8
Step-by-step explanation:
Do left part first: 0≤3x-6, 2≤x
Now do right part: 3x-6≤18, x≤8
Now combine into double inequality: 2≤x≤8
