Answer:
y = 6x + 9
Step-by-step explanation:
The equation of a line in slope- interceot form is
y = mx + c ( m is the slope and c the y- intercept )
Rearrange 2x + 12y = - 1 into this form
Subtract 2x from both sides
12y = - 2x - 1 ( divide all terms by 12 )
y = - 
x - 
← in slope- intercept form
with slope m = -
Given a line with slope m then the slope of a line perpendicular to it is
= - 
= - 
= 6
Note the line passes through (0, 9) on the y- axis ⇒ c = 9
y = 6x + 9 ← equation of perpendicular line
Answer:
x = -3/89
Step-by-step explanation:
Answer:
Step-by-step explanation:
Leaving leap years, a year contains 365 days.
For a group of 100 people, each person is independent of the other and probability of any day being his birthday has a chance of
a) Probability that exactly 3 people have same birthday = 
Each day is independent of the other
And hence no of days having exactly 3 persons birthday out of 100 persons is binomial with n = 365 and p =
Expected value of days = np = 
b) Distinct birthdays is binomail with p =1/365 and n = 365
Hence
expected value = np =1
Answer:11
Step-by-step explanation:
Boys : girls=7:1
Sum of ratio=7+1=8
Let them number of girls be y
Then they number of boys=y+66
Total number of pupils=y+y+66
Total number of pupils=2y+66
Number of girls=(girls ratio)/(sum of ratio) x (total number of pupils)
y=1/8 x (2y+66)
Cross multiply
y x 8=2y + 66
8y=2y + 66
Collect like terms
8y-2y=66
6y=66
Divide both sides by 6
6y/6=66/6
y=11
The number of girls is 11
