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3 years ago

Which ordered pair (a, b) is the solution to the following system of equations?

Mathematics

1 answer:

Kamila [148]3 years ago

8 0

Answer:

(-13, -4)

Step-by-step explanation:

It is about as easy to try the solutions as it is to find them from scratch.

However, we can determine which one it is by adding twice the second equation to the first.

(-2a +3b) +2(a -4b) = (14) +2(3)

-5b = 20

b = -4 . . . . . . matches the first choice

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the measure of the seven angles in a nonagon measure 138, 154, 145, 132, 128, 147 and 130. if the two remaining angles are equal

mars1129 [50]

A polygon is any figure sided with three sides and above such that triangle (3) is the smallest polygon. A nonagon is a polygon with 9 sides. To get the sum of interior angles of a polygon we use the formula;
(n-2) 180 or (n-4)90 where n is the number of sides.
Therefore, for a nonagon the sum of interior angles = (9-2) 180 = 1260 degrees
If we add all the angles we should get 1260, considering the remaining angles to be each x
Thus 138+154 +145 +132 +128 +147 +130 + x +x =1260
= 974 + 2x = 1260
= 2x = 286
= 143
therefore, each of the other angles was 143

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3 years ago

A garden has an area of 18 square meters. Which measurement is closest to the length of each side of the garden?

Katena32 [7]

9m is is the closest length of each side of the garden

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3 years ago

Hurry need help now 25 points!!!!!!

RSB [31]

Change in temperature = final - initial
= 22 - (-13)
= 22 + 13
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In short, Your Answer would be 35

Hope this helps!

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3 years ago

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ch4aika [34]

Answer:

m∠3 = 73°

Step-by-step explanation:

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2 years ago

without building the graph, find the coordinates of the point of intersection of the lines given by the equation y=3x-1 and 3x+y

DaniilM [7]

<h2><u>1. Determining the value of x and y:</u></h2>

Given equation(s):

$y = 3x - 1$
$3x + y = -7$

To determine the point of intersection given by the two equations, it is required to know the x-value and the y-value of both equations. We can solve for the x and y variables through two methods.

<h3 /><h3><u>Method-1: Substitution method</u></h3>

Given value of the y-variable: 3x - 1

Substitute the given value of the y-variable into the second equation to determine the value of the x-variable.

$\implies 3x + y = -7$

$\implies3x + (3x - 1) = -7$

$\implies3x + 3x - 1 = -7$

Combine like terms as needed;

$\implies 3x + 3x - 1 = -7$

$\implies 6x - 1 = -7$

Add 1 to both sides of the equation;

$\implies 6x - 1 + 1 = -7 + 1$

$\implies 6x = -6$

Divide 6 to both sides of the equation;

$\implies \dfrac{6x}{6} = \dfrac{-6}{6}$

$\implies x = -1$

Now, substitute the value of the x-variable into the expression that is equivalent to the y-variable.

$\implies y = 3(-1) - 1$

$\implies$ $\ \ = -3 - 1$

$\implies$ $= -4$

Therefore, the value(s) of the x-variable and the y-variable are;

$\boxed{x = -1}$ $\boxed{y = -4}$

<h3 /><h3><u>Method 2: System of equations</u></h3>

Convert the equations into slope intercept form;

$\implies\left \{ {{y = 3x - 1} \atop {3x + y = -7}} \right.$

$\implies \left \{ {{y = 3x - 1} \atop {y = -3x - 7}} \right.$

Clearly, we can see that "y" is isolated in both equations. Therefore, we can subtract the second equation from the first equation.

$\implies \left \{ {{y = 3x - 1 } \atop {- (y = -3x - 7)}} \right.$

$\implies \left \{ {{y = 3x - 1} \atop {-y = 3x + 7}} \right.$

Now, we can cancel the "y-variable" as y - y is 0 and combine the equations into one equation by adding 3x to 3x and 7 to -1.

$\implies\left \{ {{y = 3x - 1} \atop {-y = 3x + 7}} \right.$

$\implies 0 = (6x) + (6)$

$\implies0 = 6x + 6$

This problem is now an algebraic problem. Isolate "x" to determine its value.

$\implies 0 - 6 = 6x + 6 - 6$

$\implies -6 = 6x$

$\implies -1 = x$

Like done in method 1, substitute the value of x into the first equation to determine the value of y.

$\implies y = 3(-1) - 1$

$\implies y = -3 - 1$

$\implies y = -4$

Therefore, the value(s) of the x-variable and the y-variable are;

$\boxed{x = -1}$ $\boxed{y = -4}$

<h2><u>2. Determining the intersection point;</u></h2>

The point on a coordinate plane is expressed as (x, y). Simply substitute the values of x and y to determine the intersection point given by the equations.

⇒ (x, y) ⇒ (-1, -4)

Therefore, the point of intersection is (-1, -4).

<h3>Graph:</h3>

5 0

1 year ago