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3 years ago

Drag each equation to show if it could be a correct first step to solving the equation 3(x+8)=42.

Mathematics

1 answer:

lubasha [3.4K]3 years ago

6 0

Answer:

The 2nd, 3rd, and last equations could be a possible first step.

The rest are no's.

Step-by-step explanation:

In the second equation, the 3 was distributed.

In the 3rd, it was separately distributed.

In the last, both sides were divided by 3.

The rest are knows because every equation gives us enough information.

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Se lanza un objeto desde una plataforma.

jasenka [17]

Answer:

6 seconds

Step-by-step explanation:

The question in English is

An object is thrown from a platform.

Its height (in meters), x seconds after launch, is modeled by:

h(x)=-5x^2+20x+60

How many seconds after the launch does the object reach the ground?

Let

x ----> the time in seconds

h(x) ---> the height of the object

we have

$h(x)=-5x^2+20x+60$

we know that

When the object hit the ground the height is equal to zero

For h(x)=0

we have

$-5x^2+20x+60=60$

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

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

in this problem we have

$-5x^2+20x+60=60$

$a=-5\\b=20\\c=60$

substitute in the formula

$x=\frac{-20\pm\sqrt{20^{2}-4(-5)(60)}} {2(-5)}$

$x=\frac{-20\pm\sqrt{1,600}} {-10}$

$x=\frac{-20\pm40} {-10}$

$x=\frac{-20+40} {-10}=-2$

$x=\frac{-20-40} {-10}=6$

The solution is x=6 sec

The he object reach the ground at x=6 seconds

7 0

3 years ago

PLEASE HELP!!

Stels [109]

Answer:

the correct answer is B.-2/3

8 0

3 years ago

What is the length of the transverse axis of the conic section show below ? (y+2)^2/16-(x-3)^2/9=1

weeeeeb [17]

Would th eanswer be two solutions are the points (0,-4) and (0,4).

8 0

3 years ago

Read 2 more answers

A triangle has a base length of 14cm greater than its height . If the area of the triangle is 48cm^2, find the height of the tri

irga5000 [103]

Area of triangle = base x height /2
48 = (a+14)a/2
a^2 +14a = 96
a^2 + 14a - 96 = 0
Solving for a = 5.04

5 0

3 years ago

Read this E[2X^2 â€" Y].

djyliett [7]

Looks like a badly encoded/decoded symbol. It's supposed to be a minus sign, so you're asked to find the expectation of 2X ² - Y.

If you don't know how X or Y are distributed, but you know E[X ²] and E[Y], then it's as simple as distributing the expectation over the sum:

E[2X ² - Y] = 2 E[X ²] - E[Y]

Or, if you're given the expectation and variance of X, you have

Var[X] = E[X ²] - E[X]²

→ E[2X ² - Y] = 2 (Var[X] + E[X]²) - E[Y]

Otherwise, you may be given the density function, or joint density, in which case you can determine the expectations by computing an integral or sum.

6 0

3 years ago