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3 years ago

Evaluate x(-9)+2y when x=4, y=-1

Mathematics

2 answers:

diamong [38]3 years ago

8 0

(4)(-9) + 2 (-1) = - 38

....................................

pshichka [43]3 years ago

6 0

Answer:

= -39

Step-by-step explanation:

x(-9)+2y = -9x + 2y

if:

x = 4

y = -1

then:

-9*4 + 2*-1

-36 - 3

-39

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At the end of last year mark odometer reads 74,924 miles.at the end of this year , his odometer. reads 90,405 miles. How many mi

maks197457 [2]

Mark drove 165,329 miles year

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3 years ago

The lengths of the base of a trapezoid is 12ft and 5ft the height is 96 in what is the area of the trapezoid

lukranit [14]

The formula for the area of a trapezoid is
A = (1/2)(b₁ +b₂)h

Substitute the given information and evaluate. (Make sure all dimensions have the same units.)
A = (1/2)(12 ft +5 ft)(8 ft)
A = 68 ft²

The area of the trapezoid is 68 square feet.

8 0

3 years ago

Read 2 more answers

What is the area of the figure:

Sauron [17]

Each leg of an isosceles right triangle is sqrt(2)/2 of the hypotenuse.

The area of the figure is therefore the product of the legs divided by 2, namely

Area = 24*sqrt(2)/2 * 24*sqrt(2)/2 ÷ 2
=24² (sqrt(2))² /(2*2*2)
= 576 * 2 / (8)
= 144 sq. ft.

3 0

4 years ago

What is the x-intercept of a line that passes through the point (3,4) and has a slope of 2?

Blababa [14]

Answer:

(1,0)

Step-by-step explanation:

Hi there!

We want to find the x intercept of the line that passes through the point (3,4) and has a slope of 2

First, let's find the line

We are given both a slope, and a point. We can write the equation of the line in point-slope form, which is $y-y_1=m(x-x_1)$ , where m is the slope and $(x_1, y_1)$ is a point

We do have everything needed to write the equation, let's just label everything to avoid confusion:

m=2

$x_1=3$

$y_1$ =4

Now substitute those values as the variables that they represent into the equation:

$y-y_1=m(x-x_1)$

y-4=2(x-3)

Now we have the equation in slope-point form

The x intercept of the line is the value in which the line passes through the x axis. The value of y at this point is 0

So we can substitute y as 0 in the equation to find out the value of x:

y-4=2(x-3)

0-4=2(x-3)

Multiply

0-4=2x-6

Add 6 to both sides

0+2=2x

Simplify the left

2=2x

Divide both sides by 2

1=x

So the value of the x intercept is 1, also written as the point (1,0)

Hope this helps!

6 0

3 years ago

An article gave the accompanying data on ultimate load (kN) for two different types of beams. Assuming the underlying distributi

krok68 [10]

Answer:

The 99% confidence interval for the difference between the true average load for the fiberglass beams and that for the carbon beams is (-11.937, -6.863).

Step-by-step explanation:

We have to calculate a 99% confidence interval for the difference between the true average load for the fiberglass beams and that for the carbon beams.

The sample 1 (Fiberglass), of size n1=26 has a mean of 33.4 and a standard deviation of 2.2.

The sample 2 (Carbon), of size n2=26 has a mean of 42.8 and a standard deviation of 4.3.

The difference between sample means is Md=-9.4.

$M_d=M_1-M_2=33.4-42.8=-9.4$

The estimated standard error of the difference between means is computed using the formula:

$s_{M_d}=\sqrt{\dfrac{\sigma_1^2}{n_1}+\dfrac{\sigma_2^2}{n_2}}=\sqrt{\dfrac{2.2^2}{26}+\dfrac{4.3^2}{26}}\\\\\\s_{M_d}=\sqrt{0.186+0.711}=\sqrt{0.897}=0.9473$

The critical t-value for a 99% confidence interval is t=2.678.

The margin of error (MOE) can be calculated as:

$MOE=t\cdot s_{M_d}=2.678 \cdot 0.9473=2.537$

Then, the lower and upper bounds of the confidence interval are:

$LL=M_d-t \cdot s_{M_d} = -9.4-2.537=-11.937\\\\UL=M_d+t \cdot s_{M_d} = -9.4+2.537=-6.863$

The 99% confidence interval for the difference between the true average load for the fiberglass beams and that for the carbon beams is (-11.937, -6.863).

8 0

4 years ago