Answer:
t ≈ -2.014 or 3.647
Step-by-step explanation:
Add the opposite of the expression on the right side of the equal sign to put the equation into standard form.
4.9t² -8t -36 = 0
You can divide by 4.9 to make this a little easier to solve.
t² -(8/4.9)t -36/4.9 = 0
Now, add and subtract the square of half the x-coefficient to "complete the square."
t² -(8/4.9)t +(4/4.9)² -36/4.9 -(4/4.9)² = 0
(t -4/4.9)² -192.4/4.9² = 0 . . . . simplify
Add the constant term, then take the square root.
(t -4/4.9)² = 192.4/4.9²
t -4/4.9 = ±(√192.4)/4.9
t = (4 ± √192.4)/4.9
t ≈ {-2.014, 3.647}
Answer:
3 adult tickets and 4 child tickets
Step-by-step explanation:
a + k = 7
a = 7 - k
12a + 9k = 72
12a + 9k = 72
12(7 - k) + 9k = 72
84 - 3k = 72
84 - 3k = 72
3k = 12
k = 4
a = 3
Answer:
Subtract 11/2y from each side of the equation
Step-by-step explanation:
Answer:
She needs a grade of 71 on her next text.
Step-by-step explanation:
Mean of a data-set:
The mean of a data-set is the sum of all values in the data-set divided by the number of values.
Tammy has scored 82, 78, and 93 on her previous three tests.
Thus, her grades are 82, 78, 93 and x, in which x is her grade in the fourth test.
There are 4 tests.
What score does she need on her next test so that her average (mean) is 81?
We have to find x when the mean is 81. So
She needs a grade of 71 on her next text.
