What is 4/5 of 20 hours

Write the quadratic equation whose roots are 4 and 5, and whose leading coefficient is 4.

Umnica [9.8K]

Answer:

Answer: 4x² - 9x + 20 

Step-by-step explanation:

• General quadratic equation:

${ \rm{ {x}^{2} - (sum \: of \: roots)x + (product \: of \: roots) }}$

• sum of roots → 4 + 5 = 9

• product of roots → 4 × 5 = 20

• substitute:

${ \boxed{ \rm{4 {x}^{2} - 9x + 20 }}}$

3 0

3 years ago

What's the value of -2/5-(-9/15)?

ollegr [7]

9514 1404 393

Answer:

B. -2/5+9/15 = 3/15

Step-by-step explanation:

The only two answer choices that have -2/5 as part of the sum are B and C. Of those, choice C incorrectly represents the subtraction of -9/15.

The only reasonable choice is B.

__

The result can be reduced from 3/15 to 1/5 by removing a factor of 3 from numerator and denominator.

8 0

3 years ago

An investment is worth $3 comma 659 in 1992. By 1997 it has grown to $ 6 comma 659. Let y be the value of the investment in the

kakasveta [241]

Answer:

y = 600x + 3659

Step-by-step explanation:

General form of the linear equation:

y = mx + b

Given :

x = 0 represents 1992

x = 0 , y = 3659

So, x value for 1997 becomes:

x = 1997-1992 = 5

at x = 5, y = 6659

Plugging in x = 0, y = 3659 in y = mx+b

3659 = m(0) + b

b = 3659

Plugging in x = 5, y = 6659 and b = 3659

6659 = m(5) + 3659

Solving for m:

m(5) = 6659-3659

5m = 3000

m = 3000/5 = 600

Now plug in the values of unknowns m and b in general equation:

y = 600x + 3659

8 0

3 years ago

You are jumping off the 12 foot diving board at the municipal pool. You bounce up at 6 feet per second and drop to the water you

NARA [144]

Answer:

When do you hit the water?

1.075 seconds after you jump.

What is your maximum height?

the maximum height is 12.5626 ft

Step-by-step explanation:

The equation:

h(t) = -16*t^2 + 6*t + 12

Is the height as a function of time.

We know that the initial height is the height when t = 0s

h(0s) = 12

and we know that the diving board is 12 foot tall.

Then the zero in h(t)

h(t) = 0

Represents the surface of the water.

When do you hit the water?

Here we just need to find the value of t such that:

h(t) = 0 = -16*t^2 + 6*t + 12

Using the Bhaskara's formula, we get:

$t = \frac{-6 \pm \sqrt{6^2 - 4*(-16)*12} }{2*(-16)} = \frac{-6 \pm 28.4}{-32}$

Then we have two solutions, and we only care for the positive solution (because the negative time happens before the jump, so that solution can be discarded)

The positive solution is:

t = (-6 - 28.4)/-32 = 1.075

So you hit the water 1.075 seconds after you jump.

What is your maximum height?

The height equation is a quadratic equation with a negative leading coefficient, then the maximum of this parabola is at the vertex.

We know that the vertex of a general quadratic:

a*x^2 + b*x + c

is at

x = -b/2a

Then in the case of our equation:

h(t) = -16*t^2 + 6*t + 12

The vertex is at:

t = -6/(2*-16) = 6/32 = 0.1875

Evaluating the height equation in that time will give us the maximum height, which is:

h(0.1875) = -16*(0.1875 )^2 + 6*(0.1875) + 12 = 12.5626

And the height is in feet, then the maximum height is 12.5626 ft

6 0

3 years ago

Josue knows that his aunt earns more money. than his uncle. He asked how much his aunt earns each month and was told, "$600 less

Firdavs [7]

Answer:

Uncle's earnings is $2400

Step-by-step explanation:

Represent his uncle's earnings with x

$600 less than twice what your uncle earns is represented as:

$2x - 600$

Since, his aunt's earnings is $4200.

We have:

$2x - 600 = 4200$

Add 600 to both sides

$2x - 600 + 600= 4200 + 600$

$2x = 4800$

Solve for x

$x = 4800/2$

$x = 2400$

Hence, His uncle's earnings is $2400

5 0

4 years ago

What is 4/5 of 20 hours ​

What is 4/5 of 20 hours