Answer:
x2-5x-8=0
Step-by-step explanation:
Two solutions were found :
x =(5-√57)/2=-1.275
x =(5+√57)/2= 6.275
Reformatting the input :
Changes made to your input should not affect the solution:
(1): "x2" was replaced by "x^2".
Step by step solution :
Step 1 :
Trying to factor by splitting the middle term
1.1 Factoring x2-5x-8
The first term is, x2 its coefficient is 1 .
The middle term is, -5x its coefficient is -5 .
The last term, "the constant", is -8
Step-1 : Multiply the coefficient of the first term by the constant 1 • -8 = -8
Step-2 : Find two factors of -8 whose sum equals the coefficient of the middle term, which is -5 .
-8 + 1 = -7
-4+ 2 = -2
-2+ 4 = 2
-1 + 8 = 7
Question options :
a. They should be between 64 and 76 inches tall.
b. They should be close to the height that is 95% of the mean. That is, 66.5 inches, plus or minus 2 standard deviations.
c. They should be at or below the 95th percentile, which is 74.92 inches.
d. None of the above.
Answer: a. They should be between 64 and 76 inches tall.
Step-by-step explanation:
Given the following :
Assume men's height follow a normal curve ; and :
Mean height = 70 inches
Standard deviation= 3 inches
According to the empirical rule ;
Assuming a normal distribution with x being random variables ;
About 68% of x-values lie between -1 to 1 standard deviation of the mean. With about 95% of the x values lying between - 2 and +2 standard deviation of mean. With 99.7% falling between - 3 to 3 standard deviations from the mean.
Using the empirical rule :
95% will fall between + or - 2 standard deviation of the mean.
Lower limit = - 2(3) = - 6
Upper limit = 2(3) = 6
(-6+mean) and (+6+ mean)
(-6 + 70) and (6+70)
64 and 76
C. y - 3 = 2/3(x-3)
Nothing much to do here except examine each equation and plug in the numbers to see if it's true.
a. y + 3 = 3/2(x+3)
Try 3,3
3 + 3 = 3/2(3+3)
6 = 3/2(6). And no need to go further, it's obviously not equal.
b. y - 3 = 3/2(x-3)
Try 3,3
3 - 3 = 3/2(3-3)
0 = 3/2(0). OK. Let's try 6,5
5 - 3 = 3/2(6-3)
2 = 3/2(3)
2 = 9/2 And it's not true, so check the next one.
c. y - 3 = 2/3(x-3)
Try 3,3
3 - 3 = 2/3(3-3)
0 = 0. Check 6,5
5 - 3 = 2/3(6-3)
2 = 2/3(3)
2 = 2. Good. Both sample points work. This is the correct answer.
Just to be sure, let's check the next option
d. y + 3 = 2/3(x+3)
Try 3,3
3 + 3 = 2/3(3+3)
6 = 2/3(6). And doesn't match.
