Answer:
(- 1, - 6 )
Step-by-step explanation:
Under a counterclockwise rotation about the origin of 270°
a point (x, y ) → (y, - x ), thus
(6, - 1 ) → (- 1, - 6 )
Given:
The function is

To find:
The value of f(-1).
Solution:
We have,

Putting x=-1, we get




Therefore, the value of f(-1) is -12.
Let's translate each sentence into "Math".
Pineapple = p
Orange = x
is means equal
Pineapple is 7 times as heavy as an orange: p = 7x
Pineapple weighs 870 grams more than orange. p = 870 + x
Substitute p = 7x into the second equation:
7x = 870 + x
Subtract x from both sides
6x = 870
divide by 6
x = 145
The orange weighs 145 grams.
The pineapple weights 7 times the orange = 7(145) = 1015 grams.
Answer: 90% of people getting married for the first time get married before age of 31.13.
Step-by-step explanation:
Given : The average age (
) for a person getting married for the first time is 26 years (U.S. News and World Report, June 6, 1994).
We assume that the ages for first marriages have a normal distribution with a standard deviation (
) of 4 years.
Let x be the age before that 90% of people getting married for the first time get married.
From z-table , the value corresponds to p-value of 0.90 is 1.28155.
Formula : 

Hence, 90% of people getting married for the first time get married before age of 31.13.
If the number of ice cream sandwiches is x
And the number of cookies is y
Then
1.75x + 0.75y = 12.25
and
x + y = 11
y = 11 - x
1.75x + 0.75 (11 - x) = 12.25
1.75x + 8.25 - 0.75x = 12.25
x + 8.25 = 12.25
x = 12.25 - 8.25
x = 4
if x = 4
4 + y = 11
y = 11 - 4
y = 7
x = 4, y = 7