I believe it's
- 1 -

Hope I helped! ( Smiles )
Answer is: a= -4
STEP
1
:
1
Simplify —————
a + 3
Equation at the end of step
1
:
a 3 1
(————————+—————)-——— = 0
((a2)-9) (a-3) a+3
STEP
2
:
3
Simplify —————
a - 3
Equation at the end of step
2
:
a 3 1
(————————+———)-——— = 0
((a2)-9) a-3 a+3
STEP
3
:
a
Simplify ——————
a2 - 9
Equation at the end of step
3
:
a 3 1
(————————————————— + —————) - ————— = 0
(a + 3) • (a - 3) a - 3 a + 3
Equation at the end of step
4
:
(4a + 9) 1
————————————————— - ————— = 0
(a + 3) • (a - 3) a + 3
Pull out like factors :
3a + 12 = 3 • (a + 4)
Equation at the end of step
6
:
3 • (a + 4)
————————————————— = 0
(a + 3) • (a - 3)
3•(a+4)
——————————— • (a+3)•(a-3) = 0 • (a+3)•(a-3)
(a+3)•(a-3)
a+4 = 0
Subtract 4 from both sides of the equation :
a = -4
Answer:
a) r = 0.974
b) Critical value = 0.602
Step-by-step explanation:
Given - Two separate tests are designed to measure a student's ability to solve problems. Several students are randomly selected to take both test and the results are give below
Test A | 64 48 51 59 60 43 41 42 35 50 45
Test B | 91 68 80 92 91 67 65 67 56 78 71
To find - (a) What is the value of the linear coefficient r ?
(b) Assuming a 0.05 level of significance, what is the critical value ?
Proof -
A)
r = 0.974
B)
Critical Values for the Correlation Coefficient
n alpha = .05 alpha = .01
4 0.95 0.99
5 0.878 0.959
6 0.811 0.917
7 0.754 0.875
8 0.707 0.834
9 0.666 0.798
10 0.632 0.765
11 0.602 0.735
12 0.576 0.708
13 0.553 0.684
14 0.532 0.661
So,
Critical r = 0.602 for n = 11 and alpha = 0.05
Let car b be travelling at x mph. as they are travelling towards each other their speed of approach is (x + x + 15 ) mph. So we have the equation
speed = distance / time
2x + 15 = 250 / 2
2x = 125 - 15 = 110
x = 55 mph
Car b travels at 55 mph and car a travels at 70 mph Answer