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4 years ago

5x+4y=-14 3x+6y=6 solve the system below by the elimation

Mathematics

1 answer:

lana66690 [7]4 years ago

8 0

Answer:

y = 4

x = -6

Step-by-step explanation:

multiply first equation by 3

3×(5x+4y)= -14 ➡ 15x + 12y = -42

multiply second equation by -5

-5×(3x+6y)= 6➡ -15x -30y = -30

now add both equations up

15x +12y -15x -30y = -42 -30 (15x will eliminate -15x)

-18y = -72

y = 4 use this to find value of x

3x + 6×4 = 6 ➡ ex = -18 ➡ x = -6

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Use the fundamental identities and appropriate algebraic operations to simplify the following expression. (18 +tan x) (18-tan x)

andrezito [222]

Answer:

a) $\left(18+\tan \left(x\right)\right)\left(18-\tan \left(x\right)\right)+\sec ^2\left(x\right)=325$

b) The lowest point of $y=\cos \left(x\right)$ , $0\leq x\leq 2\pi$ is when x = $\pi$

Step-by-step explanation:

a) To simplify the expression $\left(18+\tan \left(x\right)\right)\left(18-\tan \left(x\right)\right)+\sec ^2\left(x\right)$ you must:

Apply Difference of Two Squares Formula: $\left(a+b\right)\left(a-b\right)=a^2-b^2$

$a=18,\:b=\tan \left(x\right)$

$\left(18+\tan \left(x\right)\right)\left(18-\tan \left(x\right)\right)=18^2-\tan ^2\left(x\right)=324-\tan ^2\left(x\right)$

$324-\tan ^2\left(x\right)+\sec ^2\left(x\right)$

Apply the Pythagorean Identity $1+\tan ^2\left(x\right)=\sec ^2\left(x\right)$

From the Pythagorean Identity, we know that $1=-\tan ^2\left(x\right)+\sec ^2\left(x\right)$

Therefore,

$324[-\tan ^2\left(x\right)+\sec ^2\left(x\right))]\\324[+1]\\325$

b) According with the below graph, the lowest point of $y=\cos \left(x\right)$ , $0\leq x\leq 2\pi$ is when x = $\pi$

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4 years ago

Simplify and Evaluate

zalisa [80]

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$= \dfrac{\frac{1}{2} + \frac{1}{5}}{\frac{1}{10} - \frac{1}{5^2}}$

$=\dfrac{\frac{1}{2} + \frac{1}{5}}{\frac{1}{10} - \frac{1}{25}}$

$=\dfrac{\frac{5}{10} + \frac{2}{10}}{\frac{5}{50} - \frac{2}{50}}$

$=\dfrac{\frac{7}{10}}{\frac{3}{50}}$

$= \frac{7}{10} \times \frac{50}{3}$

$= \frac{7}{1} \times \frac{5}{3}$

$= \frac{35}{3}$

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3 years ago

A rectangle has an area of 36 inches squared. Write an equation to show how the length (l) varies inversely the width (w).

Anastaziya [24]

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Assuming the last part wants you to write an equation for an x-y graph, the equation would be
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4 years ago

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blsea [12.9K]

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Step-by-step explanation: