All categories

3 years ago

Lisa wrote the expression (3x + 6x) - 2(x + 1) + 5. She simplified the expression using the following steps:

Mathematics

2 answers:

sergeinik [125]3 years ago

7 0

Answer:

Step-by-step explanation:

Alright, lets get started.

The given expression is : $(3x + 6x) - 2(x + 1) + 5$

In very first step, Lisa made a mistake.

Lisa took 3 as common factor out and what she wrote is 3 (1+x) but when she took 3 as common factor, the expression would be 3 (x+2x)

Here she made a mistake.

$3(x+2x)-2(x+1)+5$

$9x-2(x+1)+5$

$9x-2x-2+5$

$7x+3$

So, the correct answer is 7x+3 : Answer

Hope it willhelp :)

Ivanshal [37]3 years ago

6 0

Answer:

Step 1. Should be 3(x +2x) -2(x +1) +5 . . .

or . . . 3x(1 +2) -2(x +1) +5 . . .

or . . . 9x -2(x+1) +5

Step-by-step explanation:

Lisa apparently failed to realize that both terms inside the first set of parentheses have 3x as a factor. They are like terms, so could be combined directly. If Lisa really wants to factor out 3 or 3x, she could do so and then combine the remaining factors at another step.

You might be interested in

Please help 20 points

loris [4]

Answer:

10 4/7

Step-by-step i used photo math

4 0

3 years ago

Read 2 more answers

Joe has 4/5 as much money as bob. Tim has $50 more than joe. Rita has $150, which is $35 more than bob. How much money does tim

lesantik [10]

Rita = $150

Bob = $150 - $35 = $115 Bob has $115

Joe = $115 divided by 5 = $23 $23 x 4 = $92 Joe Has $92

Tim = Has $50 more then joe, $92 + $50 = $142 Tim has $142

3 0

3 years ago

X=3816371/(27×63) solve for x

skelet666 [1.2K]

Answer:

X = 14,700

Step-by-step explanation:

you can use a calculator to get the x.

X=3816371/(27×63)

8 0

3 years ago

A laboratory scale is known to have a standard deviation (sigma) or 0.001 g in repeated weighings. Scale readings in repeated we

weqwewe [10]

Answer:

99% confidence interval for the given specimen is [3.4125 , 3.4155].

Step-by-step explanation:

We are given that a laboratory scale is known to have a standard deviation (sigma) or 0.001 g in repeated weighing. Scale readings in repeated weighing are Normally distributed with mean equal to the true weight of the specimen.

Three weighing of a specimen on this scale give 3.412, 3.416, and 3.414 g.

Firstly, the pivotal quantity for 99% confidence interval for the true mean specimen is given by;

P.Q. = $\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean weighing of specimen = $\frac{3.412+3.416+3.414}{3}$ = 3.414 g

$\sigma$ = population standard deviation = 0.001 g

n = sample of specimen = 3

$\mu$ = population mean

<em>Here for constructing 99% confidence interval we have used z statistics because we know about population standard deviation (sigma).</em>

So, 99% confidence interval for the population mean, $\mu$ is ;

P(-2.5758 < N(0,1) < 2.5758) = 0.99 {As the critical value of z at 0.5% level

of significance are -2.5758 & 2.5758}

P(-2.5758 < $\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }$ < 2.5758) = 0.99

P( $-2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ < ${\bar X - \mu}$ < $2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.99

P( $\bar X-2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ < $\mu$ < $\bar X+2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.99

<u>99% confidence interval for</u> $\mu$ = [ $\bar X-2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ , $\bar X+2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ ]

= [ $3.414-2.5758 \times {\frac{0.001}{\sqrt{3} } }$ , $3.414+2.5758 \times {\frac{0.001}{\sqrt{3} } }$ ]

= [3.4125 , 3.4155]

Therefore, 99% confidence interval for this specimen is [3.4125 , 3.4155].

6 0

3 years ago

52= -5x -3 can you solve for x

Roman55 [17]

Answer:

x = -11

Step-by-step explanation:

First, add three to both sides on the equation. Then, your equation becomes 55= -5x. Finally, divide both sides by -5 to get -11 = x. So, x equals -11. Hope this helps!

4 0

3 years ago

Read 2 more answers