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3 years ago

Solve: -3x + 12 = -18

Mathematics

2 answers:

creativ13 [48]3 years ago

7 0

Answer:

x=2

Step-by-step explanation:

-3x+12=-18

-3x=-18+12

-3x=-6

x=-6/-3

x=2

Ipatiy [6.2K]3 years ago

4 0

Answer:

x=10

Step-by-step explanation:

We are given the equation:

$-3x+12= -18$

and asked to solve for x. Therefore, we must isolate x on one side of the equation.

12 is being added to -3x. The inverse of addition is subtraction. Subtract 12 from both sides of the equation.

$-3x+12-12= -18 -12$

$-3x= -18-12$

$-3x=-30$

x is being multiplied by -3. The inverse of multiplication is division. Divide both sides of the equation by -3.

$-3x/3=-30/-3$

$x= -30/-3$

$x=10$

Let's check our solution. Plug 10 in for x and solve.

$-3x+12=-18$

$-3(10)+12=-18$

Multiply -3 and 10.

$-30+12=-18$

Add 12 to -30.

$-18=-18$

This checks out, so we know our solution is correct.

The solution -3x+12=-18 is x=10.

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Nadya [2.5K]

Answer:

B!!

Step-by-step explanation:

8 0

3 years ago

Identify the surface with the given vector equation. r(s, t) = s sin 4t, s2, s cos 4t

k0ka [10]

Answer:

Circular paraboloid

Step-by-step explanation:

Given ,

$r(s,t)=ssin4t,s^2,scos4t$

Here, these are the respective $x,y,z$ axes components.

Component along x axis $r_i : ssin4t$

Component along y axis $r_j : s^2$

Component along z axis $r_k : scos4t$

We see that , from the parameterised equation , $r_i^2+r_k^2=s^2sin^24t+s^2cos^24t\\r_i^2+r_k^2=s^2\\r_i^2+r_k^2=r_j$

This can also be written as :

$x^2+z^2=y$

This is similar to an equation of a parabola in 1 Dimension.

By fixing the value of z=0,

We get $y=x^2$ which is equation of a parabola curving towards the positive infinity of y-axis and in the x-y plane.

By fixing the value of x=0,

We get $y=z^2$ which is equation of a parabola curving towards positive infinity of y-axis and in the y-z plane.

Thus by fixing the values of x and z alternatively , we get a CIRCULAR PARABOLOID.

4 0

3 years ago

The school uses between 300 and 400 sheets of paper per school day. If paper costs the school $2.00 per 100 sheets, approximatel

Nady [450]

Answer:

Option A. $140.00

Explanation:

1. Using the minimun number of sheets of paper in the interval [300, 400]

a) Cost: $ 2.00 / 100 sheets

b) 300 sheets / day × $ 2.00 / 100 sheets = $ 6.00 / day

c) Approimately 20 school days per month:

$ 6.00 / day × 20 day = $ 120.00

2. Using the maximum number of sheets of paper in the interval [300, 400]

a) Cost: $ 2.00 / 100 sheets

b) 400 sheets / day × $ 2.00 / 100 sheets = $ 8.00 / day

c) Approimately 20 school days per month:

$8.00 / day × 20 day = $ 160.00

3. Middle value:

Calculate the middle value between $160.00 and $120.00

[$120.00 + $160.00] / 2 = $140.00

Thus, the answer is the option A.

7 0

3 years ago

What is the unit rate for meters per second if a car travels 238 meters in 17 seconds?

madreJ [45]

I assume a unit rate is simply ms^-1 or whatever.

In order to determine m/s one must make the "per whatever" part equal to 1. In this case it is seconds, so we must make seconds equal to 1.

If in 17 seconds it travels 238 metres, that means in 1 second it travels 238/17m=14m

Therefore the unit rate (speed) of the car is 14m/s or 14ms^-1

6 0

3 years ago

Read 2 more answers

Construct the confidence interval for the population mean mu. c = 0.90, x = 16.9, s = 9.0, and n = 45. A 90% confidence inte

Georgia [21]

Answer:

The 90% confidence interval for population mean is $14.7 < \mu < 19.1$

Step-by-step explanation:

From the question we are told that

The sample mean is $\= x = 16.9$

The confidence level is $C = 0.90$

The sample size is $n = 45$

The standard deviation

Now given that the confidence level is 0.90 the level of significance is mathematically evaluated as

$\alpha = 1-0.90$

$\alpha = 0.10$

Next we obtain the critical value of $\frac{\alpha }{2}$ from the standardized normal distribution table. The values is $Z_{\frac{\alpha }{2} } = 1.645$

The reason we are obtaining critical values for $\frac{\alpha }{2}$ instead of that of $\alpha$ is because $\alpha$ represents the area under the normal curve where the confidence level 1 - $\alpha$ (90%) did not cover which include both the left and right tail while $\frac{\alpha }{2}$ is just considering the area of one tail which is what we required calculate the margin of error