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3 years ago

Solve by using elimination 2x-6y=18 -2x + 4y = -6 ( , )

Mathematics

1 answer:

Anna11 [10]3 years ago

3 0

Answer:

x = -9,

y = -6

Step-by-step explanation:

2x - 6y =18

-2x + 4y = -6

you can add the equations together as is and eliminate x

-2y = 12

y = -6

then plug back in,

2x - 6(-6) = 18

2x + 36 = 18

2x = -18

x= -9

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Solve h-w Solve m = for the 8 variable h. I

Ilya [14]

Answer:

1) m = h - w/8

Subtract h from both sides.

m - h = -w/8

Subtract m from both sides.

-h = -m - w/8

Divide all terms by -1.

h = m + w/8.

2) m = h - w/8

Get rid of the denominator 8 by multiplying 8/1 to all terms.

8m = 8h - w

Add w on both sides and subtract 8m from both sides.

w = 8h - 8m

3) w = x + y/z

Get rid of the denominator z by multiplying it to all terms.

wz = xz + y

Subtract xz from both sides of the equation.

wz - xz = y OR y = wz - xz

4) w = x + y/z

Subtract x from both sides.

w - x = y/z

Get rid of the denominator by multiplying it to all terms.

wz - xz = y

Now factor the expression wz - xz.

z(w - x) = y

Divide both sides by w - x.

z = y / w - x

This is read as z equals to y divided by w minus x.

5) The area of a triangle is A = 1/2bh

First, get rid of the denominator by multiplying both sides by 2.

2A = bh

To find b, divide both sides by h.

2A/h = b

6) P = kt/v

Multiply both sides by v.

Pv = kt

Divide both sides by t.

Pv/t = k OR k = Pv/t.

Step-by-step explanation:

8 0

3 years ago

Solve the equation by completing the square round to the nearest hundredth is necessary x^2-x-7=0

masha68 [24]

The answers are 3.19 or -2.19.

In order to complete the square, you must first get the constant to the other side of the equation. WE do that by adding 7 to both sides.

x^2 - x - 7 = 0

x^2 - x = 7

Now we must take half of the x coefficient (-1), which would be -.5. Then we square it and add it to both sides. This is the second step to any completing the square problem.

x^2 - x = 7

x^2 - x + .25 = 7.25

Now that we have done that, the left side will be a perfect square so that, we can factor it.

x^2 - x + .25 = 7.25

(x - .5)^2 = 7.25

After having done that, we can take the square root of both sides

(x - .5)^2 = 7.25

x - .5 = +/- $\sqrt{7.25}$

Now we can take the value of that square root and solve.

x - .5 = +/- $\sqrt{7.25}$

x - .5 = +/-2.69

x = .5 +/- 2.69

And with the + and - both there, we need to do both to get the two answers.

.5 + 2.69 = 3.19

.5 - 2.69 = -2.19

4 0

3 years ago

Which points are on the graph of f(x)=(1/3)^x?

frutty [35]

Answer:

(0,1)

Step-by-step explanation:

4 0

3 years ago

True or false If a diagonal is drawn in a parallelogram, then two congruent triangles are formed

Ksivusya [100]

Its true hope you get good grade

8 0

4 years ago

I will give brainiest to whom answers correct and the fastest and a thanks

german

Answer:

(D) The bottom graph, and (A) The top table.

Step-by-step explanation:

The easiest way to pick out the wrong answers is simply through substitution. Substitute the input into the x part of the equation that is given and if it doesn't match up with y everytime, then it is incorrect.

From table A (top table), the input x can be substituted into y = x + 2 which will come out as the output so it is correct.

For table A:

x = -3 → y = x + 2 → y = (-3) + 2 → y = -1 = -1

x = -2 → y = x + 2 → y = (-2) + 2 → y = 0 = 0

x = -1 → y = x + 2 → y = (-1) + 2 → y = 1 = 1

x = 0 → y = x + 2 → y = (0) + 2 → y = 2 = 2

x = 1 → y = x + 2 → y = (1) + 2 → y = 3 = 3

Since the table matches up with the inputs and outputs of the table, it is a correct answer.

For table B:

x = 3 → y = x + 2 → y = (3) + 2 → y = 5 = 5

x = 4 → y = x + 2 → y = (4) + 2 → y = 6 ≠ 7

x = 5 → y = x + 2 → y = (5) + 2 → y = 7 ≠ 9

x = 6 → y = x + 2 → y = (6) + 2 → y = 8 ≠ 11

x = 7 → y = x + 2 → y = (7) + 2 → y = 9 ≠ 13

5 out of the 6 y values of the table do not match the equation, so table B must be incorrect.

Graph C:

Notice how you can see the line cross the x, and y axis. When the line crosses the x axis, it is an x intercept which means y is 0. When the line crosses the y axis, it is a y intercept which means x is 0.

Since the line crosses the y axis at 2, this means that an x of 0 must lead to a y of 2 which it does.

x = 0 → y = x + 2 → y = (0) + 2 → y = 2 = 2.

But the x intercept doesn't match up as shown here.

y = 0 → y = x + 2 → (0) = x + 2 →

0 – 2 = x + 2 – 2 → -2 = x → x = -2 ≠ -1

When graphing the line y = x + 2, it's x intercept should be (-2,0). While on this graph, it's (-1,0). This means that this graph is incorrect which leads to D being another correct answer.

✓ Table A: y = x + 2

× Table B: y = 2x – 1

× Graph C: y = 2x + 2

✓ Graph D: y = x + 2

8 0

3 years ago