Answer:
1.5 seconds
Step-by-step explanation:
Since f(x) represents the distance from the ground to the rock (in feet), we just need to find the values of x for which f(x) = 340. Substituting f(x) = 340 into f(x) = -16x² - 4x + 382 gives us:
340 = -16x² - 4x + 382
0 = -16x² - 4x + 42 (Subtract 340 from both sides)
16x² + 4x - 42 = 0 (Multiply entire equation by -1, "flip" equation)
8x² + 2x - 21 = 0 (Divide entire equation by 2)
(4x + 7)(2x - 3) = 0 (Factor LHS)
4x + 7 = 0 or 2x - 3 = 0 (Zero Product Property)
4x = -7 or 2x = 3 (Subtract -7 and add 3 from/to both sides, respectively)
or 
x = -1.75 is an extraneous solution because in the context of the question, you can't have negative seconds so therefore, the final answer is 1.5 seconds.
Hope this helps!
Answer: 14 1/15
Step-by-step explanation:
4 2/5 + 9 2/3 = 13 + 6/15 + 10/15 = 13 + 16/15 = 14 1/15
So you subtract their integers by starting from the bottom then coming up to the top. And you just put the numbers in your calculator. Once you’ve got your answer for X and Y, you multiply them both. Which will give you -9/3. Next you divide -9 by 3 and 3 divided by 3. Which will give you -3/1 and just rewrite it as -3. I don’t know if this helps but I hope it does :).
If she went 10 miles upstream in the same time as she went 20 miles downstream, that means the downstream speed is twice the upstream speed.
The speed is still water is 9 mph.
The speed of the current is c.
Going downstream, the current adds speed, so the sped downstream is 9 + c.
The speed upstream is 9 - c.
9 + c is twice 9 - c.
9 + c = 2(9 - c)
9 + c = 18 - 2c
3c = 9
c = 3
Answer: The speed of the current is 3 mph.
Check:
9 + c = 12
9 - c = 6
By taking into the account the speed of the current, the downstream speed, 12 mph, is indeed twice the upstream sped, 6 mph.
Answer:
Step-by-step explanation:
Mp=$1200
Let sp be x
SP=MP-discount% of MP
x=1200-15/100 * 1200
x=120000-18000/100
x=102000/100
x=1020
the amount of money person saves=MP-SP
=$1200-$1020
=$180
therefore he saves $180
