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.
Our system of equations is:
y = -3x + 9
y = -x - 5
To solve this system of equations, we are going to use substitution. This means that we are going to substitute the second equation into the first equation since both are already solved for y in terms of x.
y = -3x + 9
-x - 5 = -3x + 9
Now, we must simplify by moving all of the constant terms to one side of the equation and all of the variable terms to the other side.
-x - 5 = -3x + 9
2x - 5 = 9
2x = 14
Finally, to undo the multiplication between the coefficient 2 and the variable x, we must divide both sides by 2 to get the variable x alone.
x = 7
Next, we must substitute in this value we have solved for x into one of the original equations to solve for the other variable, y.
y = -3x + 9
y = -3(7) + 9
To simplify, we must multiply through the parentheses and combine like terms by addition.
y = -21 + 9
y = -12
Therefore, your final answer is x = 7 and y = -12, or as an ordered pair (7, -12).
Hope this helps!
Answer: 99.7 % of the bags contain between 62 and 86 potato chips.
Step-by-step explanation:
The standard deviation given is 4.
Find the difference between the given numbers and the mean,
74-62= 12 . 86-74=12
then divide 12 by 4 to find the number of standard deviations: 12/4=3
Check a chart or diagram of the Gaussian Distribution to find that 99.7% of the samples lie within 3 standard deviations from the mean.
Answer: im almost positive its -1 1/2
Step-by-step explanation:
Answer:177
Step-by-step explanation:so for short, you need to multiply the 300 miles with the 59 precent we have and divide it to 100 this provides us the answer of miles he slept through the road trip
