Answer:
24
Step-by-step explanation:
20% of 30 = 6
30 - 6 = 24
Answer:
x = 9 + 6i or x = 9 - 6i
Step-by-step explanation:
x² - 18x + 117 = 0
Complete the square and solve:
(x - 9)² - 81 + 117 = 0
(x - 9)² + 36 = 0
(x - 9)² = -36
x - 9 = ±sqrt(-36)
x - 9 = ±sqrt(-1).sqrt(36)
i = imaginary number = sqrt(-1)
x - 9 = ±6i
x = 9 ± 6i
There are no real solutions, only imaginary ones
9 + 6i and 9 - 6i
Answer:
A recent report estimated that 25% of all college students in the United States have a sexually transmitted disease (STD). The director of the campus health center believes that the proportion of students with STDs is higher at their campus.
According to the American Heart Association guidelines, the daily maximum amount of sugar a teenager should have is 4 teaspoons. The parents of a local high school have expressed concerns that the average daily sugar intake of their students is higher than these guidelines and have been pressuring school officials to limit unhealthy snack and beverage choices offered in the cafeteria and student store.
Step-by-step explanation:
The first two researches involve the single sample compared to mean of population.
The 3rd and 4th research involves comparing samples of men and women that is two individual groups.
The solution to given system of equations is (x, y) = (2, -1)
<em><u>Solution:</u></em>
Given system of equations are:
-1x + 2y = -4 -------- eqn 1
4x + 3y = 5 ------- eqn 2
We can solve the above system of equations by elimination method
<em><u>Multiply eqn 1 by 4</u></em>
4(-1x + 2y = -4)
-4x + 8y = -16 ------ eqn 3
<em><u>Add eqn 2 and eqn 3</u></em>
4x + 3y = 5
-4x + 8y = -16
( + ) --------------------
0x + 11y = -16 + 5
11y = -11
y = -1
<em><u>Substitute y = -1 in eqn 1</u></em>
-1x + 2(-1) = -4
-x -2 = -4
-x = -4 + 2
-x = -2
x = 2
<em><u>Check the answer:</u></em>
Substitute x = 2 and y = -1 in eqn 2
4x + 3y = 5
4(2) + 3(-1) = 5
8 - 3 = 5
5 = 5
Thus the obtained answer is correct
Thus the solution to given system of equations is (x, y) = (2, -1)
