I need help with this.....skdkdidennebdndjdhdvevdhd

Sofia hits a softball straight up. the equation h= -16t^2 + 90t models the height h, in feet, of the ball after t seconds. How l

andrezito [222]

It is in the air 5.625 seconds.

Using the quadratic formula,

$t=\frac{-b\pm \sqrt{b^2-4ac}}{2a}
\\
\\=\frac{-90\pm \sqrt{90^2-4(-16)(0)}}{2(-16)}
\\
\\=\frac{-90\pm \sqrt{8100-0}}{-32}
\\
\\=\frac{-90\pm \sqrt{8100}}{-32}=\frac{-90\pm90}{-32}
\\
\\=\frac{-90+90}{-32}\text{ or }\frac{-90-90}{-32}=\frac{0}{32}\text{ or }\frac{-180}{-32}
\\
\\=0\text{ or }5.625$

0 is when the ball is first launched, 5.625 is when it hits the ground again.

4 0

2 years ago

I need this asap ty:p

Anastasy [175]

Answer:

(a) x = -2y

(c) 3x - 2y = 0

Step-by-step explanation:

You can tell if an equation is a direct variation equation if it can be written in the format y = kx.

Note that there is no addition and subtraction in this equation.

Let's put these equations in the form y = kx.

(a) x = -2y

y = x/-2 → y = -1/2x
This is equivalent to multiplying x by -1/2, so this is an example of direct variation.

(b) x + 2y = 12

2y = 12 - x
y = 6 - 1/2x
This is not in the form y = kx since we are adding 6 to -1/2x. Therefore, this is NOT an example of direct variation.

(c) 3x - 2y = 0

-2y = -3x
y = 3/2x
This follows the format of y = kx, so it is an example of direct variation.

(d) 5x² + y = 0

y = -5x²
This is not in the form of y = kx, so it is NOT an example of direct variation.

(e) y = 0.3x + 1.6

1.6 is being added to 0.3x, so it is NOT an example of direct variation.

(f) y - 2 = x

y = x + 2
2 is being added to x, so it is NOT an example of direct variation.

The following equations are examples of direct variation:

x = -2y
3x - 2y = 0

7 0

2 years ago

Read 2 more answers

Write a phrase for each expression.

AveGali [126]

Step-by-step explanation:

HERE

* 11x

Phrase= x times 11

Operation= times

* 8-y

Phrase= 8 minus y

Operation = minus

1- 7n

2- 4-y

3- 13 + x

4- x divided by 12

5- y times 10

6- c added to 3

4 0

2 years ago

Can someone help me pleaseeeeeeeee.

Leya [2.2K]

Answer:

B) 2.25

Step-by-step explanation:

Given:

x = -2

y = 4

z = -5

Work:

$\frac{x^2-z}{y} \\\\\frac{(-2)^2-(-5)}{4}\\\\\frac{4+5}{4} \\\\\frac{9}{4} \\\\2.25$

7 0

2 years ago

ΔXYZ was reflected to form ΔLMN.

goldfiish [28.3K]

ΔXYZ was reflected to form ΔLMN, hence ΔXYZ ≅ ΔLMN, ∠X ≅ ∠L and XZ ≅ LN

<h3>What is transformation?</h3>

Transformation is the movement of a point from its initial location to a new location. Types of transformation are rotation, translation, reflection and dilation.

Reflection is a rigid transformation, hence it produces congruent figures with congruent angles.

∠Y + ∠X + ∠Z = 180 (angle in a triangle)

86 + 38 + ∠Z = 180

∠Z = 56°

Also:

∠N + ∠M + ∠L = 180 (angle in a triangle)

86 + 56 + ∠L = 180

∠L = 38°

ΔXYZ was reflected to form ΔLMN, hence ΔXYZ ≅ ΔLMN, ∠X ≅ ∠L and XZ ≅ LN

Find out more on transformation at: brainly.com/question/4289712

#SPJ1

7 0

1 year ago