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4 years ago

Please let me know the correct answer.

Mathematics

1 answer:

NNADVOKAT [17]4 years ago

4 0

Set h to 640 and solve for t:

640 = -490t^2 + 1120t

Subtract 640 from both sides:

-490t^2 + 1120t - 640 = 0

The formula to solve a quadratic equation is:

x = -b -/+ sqrtroot (b^2-4ac)/(2a) where a = -490, b = 1120 and c = -640

Solve:

x = -1120 -/+ sqrtroot (1120^2-4(-490)(-640) )/ 2(-490)

x = 8/7 = 1.1428 = 1.14

Time was 1.14 seconds

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156

Sveta_85 [38]

Answer:

Third option: 80 people.

Step-by-step explanation:

Let be "x" the number of people that were surveyed.

You know that 48 people chose winter as their favorite season and these amount of people are the 60% of those questioned.

Knowing this, you can calculate the number of people that were surveyed with this procedure:

$x=\frac{(48\ people)(100\%)}{60\%}\\\\x=(48\ people)(\frac{5}{3})\\\\x=80\ people$

Therefore, 80 people were surveyed. This matches with the third option.

6 0

3 years ago

Hello, I'm trying to solve 6x + y = 4, x - 4y = 19. I have found the y but I cant seem to find the x. Plz help and we cant use d

gizmo_the_mogwai [7]

Answer:

$x=\frac{7}{5}$

$y=-\frac{22}{5}$

Step-by-step explanation:

Given:

The given expressions are.

$6x+y=4$

$x-4y=19$

We need to find x and y values.

Solution:

Equation 1⇒ $6x+y=4$

Equation 2⇒ $x-4y=19$

First solve the equation 1 for y.

$6x+y=4$

$y = 4-6x$ --------(3)

Substitute $y = 4-6x$ in equation 2.

$x-4(4-6x)=19$

Simplify.

$x-(4\times 4 - 4\times 6x)=19$

$x-(16-24x)=19$

$x-16+24x=19$

Add 16 both side of the equation.

$25x-16+16=19+16$

$25x=35$

$x=\frac{35}{25}$

Divide Numerator and denominator by 5.

$x=\frac{7}{5}$

Substitute x value in equation 3 and simplify.

$y=4-6(\frac{7}{5})$

$y=4-\frac{6\times 7}{5}$

$y=4-\frac{42}{5}$

$y=\frac{5\times 4-42}{5}$

$y=\frac{20-42}{5}$

$y=-\frac{22}{5}$ .

Therefore, the value of $x=\frac{7}{5}$ and $y=-\frac{22}{5}$ .

6 0

4 years ago

Your total at a store is $50. If you decide to use a coupon for 10% off, which expression

Mrac [35]

im gonna say d not sure, 10% is 5 dollars off tho

5 0

3 years ago

Read 2 more answers

Please help, thanks!!

kicyunya [14]

Answer:

The formula is -n × 2 = -n

Each number is multiplied by 2 to get the next number.

-25 x 2 = -50

-50 x 2 = -100

4 0

3 years ago

The following table shows Jace's earnings based on the number of hours that he works.

statuscvo [17]

Answer:

Step-by-step explanation:

because no

7 0

2 years ago