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3 years ago

2x-4y=8 x+2y=4 How many solutions (x, y) are there to the system of equations above? explain

Mathematics

1 answer:

Mekhanik [1.2K]3 years ago

6 0

Answer:

Exactly one solution.

Step-by-step explanation:

2x-4y=8

x+2y=4 /*2

2x-4y=8

2x+4y=8 (+)

4x=16

x=4

4+2y=4

y=0

(x;y)={(4; 0)}

Exactly one solution.

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Suppose the graph of a cubic polynomial function has the same zeroes and passes through the coordinate (0, -5). Write the equati

amid [387]

In this we know all three zeros and one point from which the graph pass.
So we will let specific cubic polynomial function of the form
$f(x) = a(x - x_1)(x-x_2)(x-x_3)$

As we know zeros are that point where we will get value of function equal to zero. So it is basically in form $(x_n , 0)$

SO in given question zeros are (2 , 0) , (3, 0) and (5,0)
So we can say $x_1 = 2 , x_2 = 3 , x_3 = 5$

So required equation is
$f(x) = a (x-2)(x-3)(x-5)$
              $= a[(x^2 - 2x - 3x + 6)(x-5)]$
              $= a[(x^2 - 5x+6)(x-5)]$
              $= a(x^3 - 5x^2 + 6x- 5x^2 + 25x - 30)$
              $= a(x^3 - 10x^2+31x-30)$
Now we have one point (0 , -5) from which graph passes.
So we say at x = 0 , f(x) = -5
$-5= a (0-0+0 - 30)$
$-5 = -30a$
$a = \frac{-5}{-30} = \frac{1}{6}$
So required equation of cubic polynomial is
$f(x) = \frac{1}{6}(x^3 -10x^2+31x-30)$

For finding y - intercept we simply plugin x = 0 in given equation.
As we know at x = 0 , value of function is -5.
So y - intercept is -5.

4 0

4 years ago

Read 2 more answers

The person at (0, 1) needs a bottled water. He moved to the right on a slope of -4. Where can you find him to give him the water

olga_2 [115]

You can find him at (-4,1)

5 0

3 years ago

CAN SOMEONE PLEASE WRITE A EQUATION OF THIS LINE!!

serious [3.7K]

Answer (assuming it can be in slope-intercept form):

y = -x - 1

Step-by-step explanation:

When knowing the slope of a line and its y-intercept, you can write an equation to represent it in slope-intercept form, or y = mx + b format. Substitute the m and b for real values.

1) First, find the slope of the equation, or m. Pick any two points from the line and substitute their x and y values into the slope formula, $m = \frac{y_2-y_1}{x_2-x_1}$ . I chose the points (0, -1) and (-1, 0):

$m = \frac{(0)-(-1)}{(-1)-(0)} \\m = \frac{0+1}{-1-0} \\m = \frac{1}{-1} \\m = -1$

Thus, the slope is -1.

2) Now, find the y-intercept, or b. The y-intercept of a line is the point at which the line crosses the y-axis. By reading the graph, we can see that the line intersects the y-axis at the point (0,-1), therefore that must be the y-intercept.

3) Now, substitute the found values into the y = mx + b formula. Substitute -1 for m and -1 for b:

$y = -x -1$