Round 985, 932 to the nearest thousand.

Show that 4x - x? – 7 is always<br> negative.<br><br><br><br><br> Help

Verizon [17]

<em>Question No 7</em>

Answer:

Please check the explanation.

Step-by-step explanation:

Show that 4x - x² - 7 is always negative.

Given

4x - x² - 7

4x - x² - 7 is always negative because:

-x²-7 will alwas be negative for all the values of x,

The value of - x² - 7 will always be less than 4x for all the values of x

Hence, 4x - x² - 7 is always negative

For example,

let suppose we enter x = 1

$4(1)-1^{2} -7\\=4-1-7\\=4-8\\=-4$

let suppose we enter x = -1

$4(-1)-(-1)^{2} - 7\\= -4 - 1 - 7\\= -12$

6 0

3 years ago

Which expression is equivalent to the following complex fraction?

user100 [1]

The equivalent expression of $(1 + \frac{1}{y}) \div (1-\frac 1y)$ is $\frac{y + 1}{y-1}$

<h3>How to determine the equivalent fraction?</h3>

The fraction is given as:

$(1 + \frac{1}{y}) \div (1-\frac 1y)$

Take the LCM

$\frac{y + 1}{y} \div \frac{y-1}y$

Express as products

$\frac{y + 1}{y} \times \frac{y}{y-1}$

Evaluate the product

$\frac{y + 1}{y-1}$

Hence, the equivalent expression of $(1 + \frac{1}{y}) \div (1-\frac 1y)$ is $\frac{y + 1}{y-1}$

Read more about equivalent expression at:

brainly.com/question/24734894

#SPJ1

4 0

2 years ago

4 of 4

Vlada [557]

Answer:

£30

Step-by-step explanation:

Let Brian initially had money in his wallet = £x

and Colin had the money = £y

Since ratio of money in Brian's wallet to Colin's wallet was 5 : 1

Therefore,

⇒ x = 5y -------(1)

Brian spent £27 that day, so money left with him = £(x - 27)

After spending the money Brian had £3 less than Colin.

(x - 27) = (y - 3)

x = y + 27 - 3

x = y + 24 -------(2)

Now we equate the equations (1) and (2) for the value of x,

5y = y + 24

5y - y = 24

4y = 24

y = £6

From equation (2),

x = 6 + 24

x = £30

Therefore, Brian initially had £30.

i hope this helps

3 0

3 years ago

Will mark brainliest if get the correct answer.

Savatey [412]

Answer:

Perimeter of rectangle before folded = 56 in

Total area after folding = 156 sq in

Step-by-step explanation:

Rectangle before folded: l = 16 and w = 12

P = 2(16) + 2(12) = 32 + 24 = 56 in.

Figure after folding: Area of trapezoid + area of rectangle

Area of trapezoid = h( $b_{1} + b_{2}$ )/2 = 6(4 + 16)/2 = 60

Area of rectangle = lw = 16(6) = 96

Total area after folding = 60 + 96 = 156 sq in.

Note: You could also find the area after folding by substracting the areas of the two triangles in the corners from the area of the original rectangle. Your choice. OK?

8 0

3 years ago

Jessie recently drove to visit her parents who live 240240 miles away. On her way there her average speed was 2525 miles per hou

dusya [7]

Answer:

The speed/rate to her parent's house is x = 75 mph

The speed/rate from her parent's house is y = 50 mph

Step-by-step explanation:

Given;

Distance to her parent's house = 240 miles

Total distance travelled (to and fro) = 240×2 = 480 miles

Total time taken t = 8 hours

On her way there her average speed was 25 miles per hour faster than on her way home (she ran into some bad weather)

Let x and y represent her speed to and from her parent's house respectively.

x = y+25 ......1

The time taken to her parent's house is;

time = distance/velocity

t1 = 240/x = 240/(y+25)

The time taken from her parent's house is;

time = distance/velocity

t2 = 240/y

Total time taken t = t1 +t2

t = 240/(y+25) + 240/y = 8

Solving for y ;

(240y + 240(y+25))/(y^2 +25y) = 8

Cross multiply;

240y + 240y+6000 = 8y^2 + 200y

480y +6000 = 8y^2 + 200y

8y^2 + 200y -480y -6000 = 0

8y^2 - 280y - 6000 = 0

Divide through by 8;

y^2 - 35y - 750 = 0

Solving the quadratic equation;

y = 50

or

y = -15

Velocity cannot be negative, so y = 50mph

From equation 1;

x = y+25

Substituting y =50

x = 50 + 25

x = 75 mph

The speed/rate to her parent's house is x = 75 mph

The speed/rate from her parent's house is y = 50 mph

3 0

3 years ago