Answer:
B. 3
Step-by-step explanation:
If you were to multiply the top equation by 3 then the x value for the first equation would be 6 and since the bottom equation's x value is -6, if you were to add them, they would cancel eachother off.
LOL hope this makes sense :) Please give brainliest!! Thanks!!
Answer:
27
Step-by-step explanation:
Remember to follow PEMDAS. Note that, when multiplying or dividing:
1) one positive and one negative = negative number
2) two positive = positive number
3) two negative = positive number
(-7)(-5) = -7 * -5 = 35
+(-8) = +1 * -8 = -8
Subtract:
35 - 8 = 27
27 is your answer.
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Answer:
4x³
Step-by-step explanation:
d/dx ln(x⁴ + 7) = 1/(x⁴ + 7) × _?
To obtain the missing expression, let us simplify d/dx ln(x⁴ + 7). This can be obtained as follow:
Let y = ln (x⁴ + 7)
Let u = (x⁴ + 7)
Therefore,
ln(x⁴ + 7) = ln u
Thus,
y = ln u
dy/du = 1/u
Next, we shall determine du/dx. This is illustrated below:
u = (x⁴ + 7)
du/dx = 4x³
Finally, we shall determine dy/dx of ln (x⁴ + 7) as follow:
dy/dx = dy/du × du/dx
dy/du = 1/u
du/dx = 4x³
dy/dx = 1/u × 4x³
But:
u = (x⁴ + 7)
Therefore,
dy/dx = 1/(x⁴ + 7) × 4x³
Thus, the missing expression is 4x³
No, the decimal will be over four places
Answer:
The expected number of keys she will try before she opens the door is 4.5.
Step-by-step explanation:
A woman has eight keys on a key ring, one of which fits the door she wants to unlock.
Each of them is equally as likely to be the one to work, which means that this situation is represented by an uniform distribution with lower bound 
and upper bound 
.
Find the expected number of keys she will try before she opens the door.
The expected value of the uniform distribution is given by:
Considering 
, as is the case in this exercise:
The expected number of keys she will try before she opens the door is 4.5.
