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natima [27]
3 years ago
15

Identify any extraneous soloution. See pic above

Mathematics
1 answer:
Wewaii [24]3 years ago
7 0

Answer:

x = 3

Step-by-step explanation:

Given

\sqrt{-x+4} = x - 4 ( square both sides )

- x  4 = (x - 4)² ← expand

- x + 4 = x² - 8x + 16 ( subtract - x + 4 from both sides )

0 = x² - 7x + 12 ← in standard form

0 = (x - 3)(x - 4) ← in factored form

Equate each factor to zero and solve for x

x - 3 = 0 ⇒ x = 3

x - 4 = 0 ⇒ x = 4

As a check

Substitute these values into the equation and if both sides are equal then they are the solutions

x = 3 : \sqrt{-3+4} = \sqrt{1} = 1

right side = 3 - 4 = - 1

left side ≠ right side ⇒ extraneous solution

x = 4 : \sqrt{-4+4} = 0 and right side = 4 - 4 = 0

left side = right side ⇒ x = 4 is the solution

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find two consecutive integers such that ten more than twice the smaller is seven less than three times the larger
Radda [10]
This is how I would work it out:

1st no. = x+1                 2x+10=3(x+1)-7
2nd no. = x                    2x+10=3x-4
                                              x=14   

1st no. is 15; 2nd no. is 14 

To check: 28+10=38; three times the larger is 45; and 38 is 7 less than 45.


6 0
3 years ago
8
Nata [24]

Answer: 15, -8

Step-by-step explanation:

u_2=7\\u_2=u_1+r\\u_3=u_1+2r\\u_4=u_1+3r\\\\u_1+u_2+u_3+u_4=4u_1+6r=12\\u_1+r=7\\\\

\left \{ \begin {array} {ccc|c|c}u_1+r&=&7&-4&-6\\4u_1+6r&=&12&1&1\\\end {array} \right.\\\\\\\left \{ \begin {array} {ccc}2r&=&-16\\-2u_1&=&-30\\\end {array} \right.\\\\\\\left \{ \begin {array} {ccc}r&=&-8\\u_1&=&15\\\end {array} \right.\\\\\\Proof:\\u_1=15\\u_2=7\\u_3=-1\\u_4=-9\\sum=12\\

6 0
2 years ago
A boat traveled 27 miles in 2 hours. At this, how many miles will the boat travel in 1/2 hour?
Fantom [35]
You do distance over time to get the rate, so you'd do 27/2= 13.5mph then divide that in half since you're asking for the distance traveled in half that hour so you do 13.5/2 and you get 6.75 miles traveled in half and hour.
4 0
2 years ago
A person on tour has dollar 360 for his daily expenses. If he extends his tour for 4 days, he has to cut down his daily expenses
mash [69]

Answer:

The original duration of the tour = 20 days

Step-by-step explanation:

Solution:

Total expenses for the tour = $360

Let the original tour duration be for x days.

So, for x days the total expense = $360

<em>Thus the daily expense in dollars can be given by</em> = \frac{360}{x}

Tour extension and effect on daily expenses.

The tour is extended by 4 days.

<em>Tour duration now</em> = (x+4) days

On extension, his daily expense is cut by $3

<em>New daily expense in dollars </em>= (\frac{360}{x}-3)

Total expense in dollars can now be given as:  (x+4)(\frac{360}{x}-3)

Simplifying by using distribution (FOIL).

(x.\frac{360}{x})+(x(-3)+(4.\frac{360}{x})+(4(-3))

360-3x+\frac{1440}{x}-12

348-3x+\frac{1440}{x}

We know total expense remains the same which is = $360.

So, we have the equation as:

348-3x+\frac{1440}{x}=360

Multiplying each term with x to remove fractions.

348x-3x^2+1440=360x

Subtracting 348x both sides

348x-348x-3x^2+1440=360x-348x

-3x^2+1440=12x

Dividing each term with -3.

\frac{-3x^2}{-3}+\frac{1440}{-3}=\frac{12x}{-3}

x^2-480=-4x

Adding 4x both sides.

x^2+4x-480=-4x+4x

x^2+4x-480=0

Solving using quadratic formula.

For a quadratic equation: ax^2+bx+c=0

x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}

Plugging in values from the equation we got.

x=\frac{-4\pm\sqrt{(4)^2-4(1)(-480)}}{2(1)}

x=\frac{-4\pm\sqrt{16+1920}}{2}

x=\frac{-4\pm\sqrt{1936}}{2}

x=\frac{-4\pm44}{2}

So, we have

x=\frac{-4+44}{2}   and x=\frac{-4-44}{2}

x=\frac{40}{2}   and x=\frac{-48}{2}

∴ x=20           and x=-24

Since number of days cannot be negative, so we take x=20 as the solution for the equation.

Thus, the original duration of the tour = 20 days

6 0
3 years ago
Sam rented a truck for one day. There was a base fee of $16.95, and there was an additional charge of 73 cents for each mile dri
Naddik [55]

Answer:  134 miles

Step-by-step explanation:  

f(m) = 16.95 + 0.92m

140.23 = 16.95 + 0.92m

0.92m = 140.23 - 16.95

0.92m = 123.28

m = 123.28/0.92

m = 134 miles

5 0
2 years ago
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