Answer:
A. (x + 2)^2 = 31.
Step-by-step explanation:
x^2 + 4x = 27
x^2 + 4x - 27 = 0
A. (x + 2)^2 = 31
x^2 + 4x + 4 - 31 = 0
x^2 + 4x - 27 = 0
This option corresponds to the given equation, so it is correct.
B. (x + 2)^2 = 43
x^2 + 4x + 4 - 43 = 0
x^2 + 4x - 39 = 0
This does not correspond to the equation.
C. (x + 4)^2 = 31
x^2 + 8x + 16 - 31 = 0
x^2 + 8x - 15 = 0
This does not correspond to the equation.
D. (x+4)^2 = 43
x^2 + 8x + 16 - 43 = 0
x^2 + 8x - 27 = 0
This does not correspond to the equation.
So, your answer is A. (x + 2)^2 = 31.
Make sure to SUBMIT and check your PREVIOUS answers to make sure they are right! XD Also, hope this helps!
Answer: 2?
Step-by-step explanation:
Answer: <u>4 pounds</u> of brand X sugar
====================================================
Reason:
n = number of pounds of brand X sugar
5n = cost of buying those n pounds, at $5 per pound
Brand Y costs $2 per pound, and you buy 8 lbs of it, so that's another 2*8 = 16 dollars.
5n+16 = total cost of brand X and brand Y combined
n+8 = total amount of sugar bought, in pounds
3(n+8) = total cost because we buy n+8 pounds at $3 per pound
The 5n+16 and 3(n+8) represent the same total cost.
Set them equal to each other. Solve for n.
5n+16 = 3(n+8)
5n+16 = 3n+24
5n-3n = 24-16
2n = 8
n = 8/2
n = 4 pounds of brand X sugar are needed
-------------
Check:
n = 4
5n = 5*4 = 20 dollars spent on brand X alone
16 dollars spent on brand Y mentioned earlier
20+16 = 36 dollars spent total
n+8 = 4+8 = 12 pounds of both types of sugar brands combined
3*12 = 36 dollars spent on both types of sugar brands
The answer is confirmed.
--------------
Another way to verify:
5n+16 = 3(n+8)
5*4+16 = 3(4+8)
20+16 = 3(12)
36 = 36
Using the unit circle, the coordinates of 3π/4 is :
![(-\frac{\sqrt[]{2}}{2},\frac{\sqrt[]{2}}{2})](https://tex.z-dn.net/?f=%28-%5Cfrac%7B%5Csqrt%5B%5D%7B2%7D%7D%7B2%7D%2C%5Cfrac%7B%5Csqrt%5B%5D%7B2%7D%7D%7B2%7D%29)
Note that tangent function can be solved using the formula y/x
where x and y are the coordinates of the angle.
This will be :
![\frac{\sqrt[]{2}}{2}\div(-\frac{\sqrt[]{2}}{2})=-1](https://tex.z-dn.net/?f=%5Cfrac%7B%5Csqrt%5B%5D%7B2%7D%7D%7B2%7D%5Cdiv%28-%5Cfrac%7B%5Csqrt%5B%5D%7B2%7D%7D%7B2%7D%29%3D-1)
The answer is -1
Answer:13
Step-by-step explanation:
