I'm assuming you meant to write 8^(-2) or 
where the -2 is the exponent over the 8.
If my assumption is correct, then we use the rule 
So,
<h3>Answer: Choice D. 1/64</h3>
Answer:
B. 66
Step-by-step explanation:
45% of 400
.45 x 400 = 180 (number of girls)
400 - 180 = 220 (number of boys)
30% of 220
.30 x 220 = 66
This is a simple system of equations. We first write the words in math as 4x + 6y = 36 and 5y - 3x = 49.
Now we isolate 5 in the second equation to get 5y = 49+3x or y=(49+3x)/5. We can now substitute our value for y into our first equation and simplify.
4x + 6y = 36 is the same as 4x+6((49+3x)/5) = 36. This can be simplified to 4x+(294+18x)/5 = 36, which is the same as 20x+294+18x = 180. We can combine like terms to get 38x +294 = 180 or 38x = -114. Now we divide by 38 on both sides to get x = -3.
Now that we have our value for x, we substitute that value into the second equation and solve for y.
5y - 3x = 49 is the same as 5y - 3(-3) = 49 or 5y+9 = 49. This can be simplified to 5y=40 or y=8.
Our values for x and y are -3 and 8. Hope this helps!
Answer:
(x+4)^2=-8(y+3)
Step-by-step explanation:
Given:
focus of parabola=(-4,-5)
directrix= -1
Standard form of parabola :
(x - h)^2 = 4p (y - k),
where focus is:
(h, k + p)
directrix is :
y = k - p
Now equating the values we get
(-4,-5) = (h,k+p)
h=-4
k+p=-5
k=-5-p
Also
y=-1 and y=k-p
i.e. k-p=-1
Substituting k=-5-p in above we get:
-5-p-p=-1
-2p=-1+5
p=4/-2
p=-2
Putting p=-2 in k-p=-1 we get:
k=-1-2
k=-3
Putting all the values in standard formula for parabola we get:
(x - (-4))^2 = 4(-2) (y -(-3))
(x+4)^2=-8(y+3)!
Answer:
y = 9
Step-by-step explanation:
(3 + 3 + 16 + 19 + y)5 = 10
41 + y = 5*10
y = 50-41
y = 9
