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3 years ago

Y = x - 4 -2x + y = 18 Use elimination pls

Mathematics

2 answers:

Aleks [24]3 years ago

8 0

Answer:

x = -22 , y = -26

Step-by-step explanation:

Solve the following system:

{y = x - 4 | (equation 1)

y - 2 x = 18 | (equation 2)

Express the system in standard form:

{-x + y = -4 | (equation 1)

-(2 x) + y = 18 | (equation 2)

Swap equation 1 with equation 2:

{-(2 x) + y = 18 | (equation 1)

-x + y = -4 | (equation 2)

Subtract 1/2 × (equation 1) from equation 2:

{-(2 x) + y = 18 | (equation 1)

0 x+y/2 = -13 | (equation 2)

Multiply equation 2 by 2:

{-(2 x) + y = 18 | (equation 1)

0 x+y = -26 | (equation 2)

Subtract equation 2 from equation 1:

{-(2 x)+0 y = 44 | (equation 1)

0 x+y = -26 | (equation 2)

Divide equation 1 by -2:

{x+0 y = -22 | (equation 1)

0 x+y = -26 | (equation 2)

Collect results:

Answer: {x = -22 , y = -26

Nana76 [90]3 years ago

8 0

Answer:

Step-by-step explanation:

$\left\{\begin{array}{ccc}y=x-4&\text{subtract}\ x\ \text{from both sides}\\-2x+y=18\end{array}\right\\\\\left\{\begin{array}{ccc}-x+y=-4\\-2x+y=18&\text{change the signs}\end{array}\right\\\underline{+\left\{\begin{array}{ccc}-x+y=-4\\2x-y=-18\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad x=-22\\\\\text{Put the value of}\ x\ \text{to the first equation:}\\\\y=-22-4\\y=-26$

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Answer:

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Step-by-step explanation:

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2 years ago

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2 years ago

What is the factorization of 1000x^6 - 27?

OverLord2011 [107]

Answer:

Step-by-step explanation:

Cube root 1000x^6 = 10x^2

Cube root of - 27 = 3

So the first part of the factorization process is 10x^2 - 3. There is no help here because all of the answers give this binomial as the first factor.

The second factor is (10x^2)^2 + (3)*10x^2 + 3^2)

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2 years ago

HELPPPP ME PLZZZZ!!!!!!

mihalych1998 [28]

<h3>Answers:</h3>

14. Each leg is $21\sqrt{2}$ units long.

15 (a). The longer leg is $7\sqrt{3}$ units long

15 (b). The hypotenuse is $14$ units long

=====================================================

Explanations:

For a 45 degree right triangle, aka 45-45-90 triangle, the hypotenuse is equal to sqrt(2) times the short leg. Algebraically we can say

$y = x\sqrt{2}$ where x is the leg and y is the hypotenuse

Let's solve for x

$y = x\sqrt{2}\\\\x\sqrt{2} = y\\\\x = \frac{y}{\sqrt{2}}\\\\x = \frac{y\sqrt{2}}{\sqrt{2}*\sqrt{2}} \ \text{rationalizing denominator}\\\\x = \frac{y\sqrt{2}}{2}\\\\$

Now plug in the given hypotenuse y = 42, this leads to,

$x = \frac{y\sqrt{2}}{2}\\\\x = \frac{42\sqrt{2}}{2}\\\\x = \frac{42}{2}\sqrt{2}\\\\x = 21\sqrt{2}\\\\$

---------------------------

For a 30-60-90 triangle, the hypotenuse is double that of the short leg. So the hypotenuse is 2*7 = 14.

The longer leg is equal to sqrt(3) times the short leg. The longer leg is $7\sqrt{3}$

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