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3 years ago

Can someone explain this step by step please

Mathematics

1 answer:

kobusy [5.1K]3 years ago

3 0

Answer:

x = - 2

y = 6

Step-by-step explanation:

The best way to do this is to put - 3x in for y in the second equation.

4x - 2(-3x) = - 20 Watch the signs. You have 2 minus signs.

4x - - 6x = -20 Change - - 6x to 6x

4x + 6x = - 20 Add

10x = - 20 Divide by 10

x = -20/10

x = - 2

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

Find y

y = - 3x

y = -3 * -2

y = 6

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harkovskaia [24]

Answer:

2.29

Step-by-step explanation:

First determine the square root of 17.8

√17.8 = 4.22

second, determine the value of $1.3^{2.5}$ = 1.93

subtract 1.93 from 4.22

4.22 - 1.93 = 2.29

6 0

3 years ago

What is -3 = z - 8 (solve the equation, check the solution)

laila [671]

Answer:

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Step-by-step explanation:

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3 years ago

Work out the diffeence beteeen 77.5 and 2.27

Stella [2.4K]

77.5
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3 years ago

Read 2 more answers

How do I verify #15 using fundamental trig identities?

expeople1 [14]

We start with the more complicated side which is the left side, and show that, on using some trigonometric identities, we will get the term on the right side .

$\frac{sin \theta + tan \theta}{1+cos \theta}$

Using Quotient identity for tangent function, we will get

$\frac{sin \theta+ \frac{sin \theta}{cos \theta}}{1+cos \theta}$

$\frac{sin \theta cos \theta + sin \theta}{cos \theta(1+cos \theta)}$

Taking out sine function from the numerator

$=\frac{sin \theta(1+cos \theta)}{cos \theta(1+cos \theta)}$

Cancelling the common term of numerator and denominator

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3 years ago

Use completing the square to solve for x in the equation (x+7)(x-9) = 25.

balandron [24]

Answer:

x = 1 ±√89

Step-by-step explanation:

We have the equation:

(x+7)(x-9) = 25

Using distributive property:

x(x-9) + 7(x-9) = 25

x²- 9x + 7x - 63 -25 = 0

x²- 2x - 88 = 0

To complete squares we need to add and subtract 1, as follows:

x²- 2x - 88 +1 -1 = 0

x²- 2x +1 -88 -1 = 0 (this is a perfect square)

(x - 1)² - 89 = 0

Solving for x:

(x - 1)² = 89

x - 1 = ±√89

x = 1 ±√89

6 0

3 years ago