7x - 5y = 21....(4,?)...so sub in 4 for x and solve for y
7(4) - 5y = 21
28 - 5y = 21
-5y = 21 - 28
-5y = - 7
y = 7/5
check..
7(4) - 5(7/5) = 21
28 - 35/5 = 21
28 - 7 = 21
21 = 21 (correct)
the other coordinate is 7/5......(4,7/5)
Answer:
after 10 seconds the charge is 1.624
Step-by-step explanation:
I think your question missed key information, allow me to add in and hope it will fit the orginal one.
The electrical charge on a metal plate is given by the function below, where t is the time in seconds. What is the charge after 10 seconds?
C (t) = 12
My answer:
Given the information:
C (t) = 12
when t =10 we have:
C (10) = 12
<=> C (10) = 12
<=> C (10) = 12
<=> C (10) = 12 * 0.1353
<=> C (10) = 1.624
Hence, after 10 seconds the charge is 1.624
Answer:
(2n - 7) - 10
Step-by-step explanation:
(2n - 7) represents "difference of 2 times a number and 7"
- 10 represents "10 less"
Answer:
x³ - (√2)x² + 49x - 49√2
Step-by-step explanation:
If one root is -7i, another root must be 7i. You can't just have one root with i. The other roos is √2, so there are 3 roots.
x = -7i is one root,
(x + 7i) = 0 is the factor
x = 7i is one root
(x - 7i) = 0 is the factor
x = √2 is one root
(x - √2) = 0 is the factor
So the factors are...
(x + 7i)(x - 7i)(x - √2) = 0
Multiply these out to find the polynomial...
(x + 7i)(x - 7i) = x² + 7i - 7i - 49i²
Which simplifies to
x² - 49i² since i² = -1 , we have
x² - 49(-1)
x² + 49
Now we have...
(x² + 49)(x - √2) = 0
Now foil this out...
x²(x) - x²(-√2) + 49(x) + 49(-√2) = 0
x³ + (√2)x² + 49x - 49√2
