All categories

4 years ago

Determine which ordered pairs are solutions to the equation 3x+7y=21

Mathematics

1 answer:

mafiozo [28]4 years ago

7 0

Answer:

(0,3) and (7,0) are solutions.

Step-by-step explanation:

In a pair of coordinates, they are always listed as (x,y). Since this is the case, you plug in each coordinate to their respective places.

For (0,3)

3(0) + 7(3) = 21

0 + 21 = 21

For (7,0)

3(7) + 7(0) = 21

21 + 0 = 21

To double check that (1,2) isn't a solution:

3(1) + 7(2) = 21

3 + 14 = 21

17 = 21 X

This doesn't work.

Marking as Brainliest is much appreciated.

You might be interested in

FINDDD VALUE OF Y!!!!

solmaris [256]

Answer:

The sum of the internal ángles = 360°

(3y+40)° and (3x-70°) are suplementary angles = 180°

then:

(3x-70) + (3y+40) + 120 + x = 360 ⇒ first eq.

(3y+40) + (3x-70) = 180 ⇒ second eq

development:

from the first eq.

3x + x + 3y = 360 + 70 - 40 - 120

4x + 3y = 430 - 160

4x + 3y = 270 ⇒ third eq.

3y = 270 - 4x

y = (270 - 4x) / 3 ⇒ fourth eq.

from the secon eq.:

3y + 3x = 180 + 70 - 40

3y + 3x = 250 - 40

3y + 3x = 210 ⇒ fifth eq.

multiply by -1 the fifth eq and sum with the third eq.

-3y - 3x = -210 ⇒ (fifth eq. *-1)

3y + 4x = 270

⇒ 0 + x = 60

x = 60°

from the fourth eq.

y = (270-4x)/3

y = (270-(4*60)) / 3

y = (270 - 240) / 3

y = 30/3

y = 10°

Probe:

from the first eq.

(3x-70) + (3y+40) + 120 + x = 360

3*60 - 70 + 3*10 + 40 + 120 + 60 = 360

180 - 70 + 30 + 40 + 120 + 60 = 360

180 + 30 + 40 + 120 + 60 - 70 = 360

430 - 70 = 360

Answer:

y = 10

7 0

3 years ago

<img src="https://tex.z-dn.net/?f=%28x%5E%7B2%7D%20%2Bx-3%29%3A%20%28x%5E%7B2%7D%20-4%29%5Cgeq%201" id="TexFormula1" title="(x^{

Jlenok [28]

Answer:

$x>2$

Step-by-step explanation:

When given the following inequality;

$(x^2+x-3):(x^2-4)\geq1$

Rewrite in a fractional form so that it is easier to work with. Remember, a ratio is another way of expressing a fraction where the first term is the numerator (value over the fraction) and the second is the denominator(value under the fraction);

$\frac{x^2+x-3}{x^2-4}\geq1$

Now bring all of the terms to one side so that the other side is just a zero, use the idea of inverse operations to achieve this:

$\frac{x^2+x-3}{x^2-4}-1\geq0$

Convert the (1) to have the like denominator as the other term on the left side. Keep in mind, any term over itself is equal to (1);

$\frac{x^2+x-3}{x^2-4}-\frac{x^2-4}{x^2-4}\geq0$

Perform the operation on the other side distribute the negative sign and combine like terms;

$\frac{(x^2+x-3)-(x^2-4)}{x^2-4}\geq0\\\\\frac{x^2+x-3-x^2+4}{x^2-4}\geq0\\\\\frac{x+1}{x^2-4}\geq0$

Factor the equation so that one can find the intervales where the inequality is true;

$\frac{x+1}{(x-2)(x+2)}\geq0$

Solve to find the intervales when the equation is true. These intervales are the spaces between the zeros. The zeros of the inequality can be found using the zero product property (which states that any number times zero equals zero), these zeros are as follows;

$-1, 2, -2$

Therefore the intervales are the following, remember, the denominator cannot be zero, therefore some zeros are not included in the domain

$x\leq-2\\-2$

Substitute a value in these intervales to find out if the inequality is positive or negative, if it is positive then the interval is a solution, if it is negative then it is not a solution. This is because the inequality is greater than or equal to zero;

$x\leq-2$ -> negative

$-2$ -> neagtive

$-1\leq x$ -> neagtive

$x>2$ -> positive

Therefore, the solution to the inequality is the following;

$x>2$

6 0

3 years ago

S What is the value of PS in the triangle above? (A) 5/2 (B) 10 (C) 11 (D) 13

makkiz [27]

Answer:

Step-by-step explanation:

7 0

3 years ago

I can’t figure this out at all.

Liula [17]

The fact that this triangle is a right angle triangle makes you now have 2 angles and the 1 side given, so it should be solvable.
First, You know that A=46 and C=90 as it is the right angle, and you know that the sum of any triangle's angles is 180. so now B=180-(90-46)=44
Now to the sides,
sin(B)=opp./hyp.=b/c=8/c=sin(44)
so, c=8/sin(44) which is approximately 11.52 unit length
now, use Pythagoras to find a,
a=√c²-b² =√11.52²-8² which is approximately 8.3 unit length.
Hope this helps.

6 0

3 years ago

X^2 - 9x -10 =0 has a discriminant of: a. 121 b. 72 c. -359 d. 41 e. 136

Feliz [49]

In the standard form of quadratic
$ax^{2} +bx+c$
the discriminant is
$b^{2} -4ac$
In your quadratic, a = 1, b = -9 and c = -10
Now you need to plug these values into the expression for the discriminant.

7 0

3 years ago