Answer:
k = 1
Step-by-step explanation:
English Translation
Find k if the point P (-1, 2k + 1) belongs to the graph of the function f (x) = - 4x^2 + 7.
The function is given as
y = f(x) = -4x² + 7
and point (-1, 2k+1) lies on the graph.
This point means that, at x = -1, y = 2k+1
y = -4x² + 7
Substituting the values in
2k + 1 = -4(-1)² + 7
2k + 1 = -4 + 7 = 3
2k = 3 - 1
2k = 2
k = 1
Hence, the point (-1, 2k+1) is (-1, 3)
To check,
y = -4x² + 7
3 = -4(-1)² + 7
3 = -4 + 7
3 = 3
So, this is truly correct.
Hope this Helps!!!
25600
Do 80/100 * 80,000 to find how many voters actually voted (it should be 64,000). Then it says that 60% of those people voted for A, so that means 40% of them voted for B. Do 40/100 times 64,000
Answer:
see below
Step-by-step explanation:
24 - 3 x = -27
Subtract 24 from each side
24-24 - 3 x = -27-24
-3x =-51
Divide each side by -3
-3x/-3 = -51/-3
x = 17
Check
24 -3(17) = -27
24 -51 = -27
-27 = -27
Answer:
w= 9
Step-by-step explanation:

Square both sides:
-4w +61= (w -4)²

Expand:
-4w +61= w² -2(w)(4) +4²
-4w +61= w² -8w +16
Simplify:
w² -8w +16 +4w -61= 0
w² -4w -45= 0
Factorize:
(w -9)(w +5)= 0
w -9= 0 or w +5= 0
w= 9 or w= -5 (reject)
Note:
-5 is rejected since we are only taking the positive value of the square root here. If the negative square root is taken into consideration, then w= -5 would give us -9 on both sides of the equation.
<u>Why </u><u>do </u><u>we </u><u>use </u><u>negative </u><u>square </u><u>root?</u>
When solving an equation such as x²= 4,
we have to consider than squaring any number removes the negative sign i.e., the result of a squared number is always positive.
In the case of x²= 4, x can be 2 or -2. Thus, whenever we introduce a square root, a '±' must be used.
However, back to our question, we did not introduce the square root so we should not consider the negative square root value.
(not sure if this is right but)
x (to the 2nd power) + y (to the 2nd power) = cos (90) (to the 2nd power)