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3 years ago

If x2 = 30, what is the value of x?

Mathematics

2 answers:

nataly862011 [7]3 years ago

6 0

Subtract 30, then factor the equation.

... x² = 30

... x² - 30 = 0

... (x -√30)(x +√30) = 0

By the zero product rule, the solutions are values of x that make a factor be zero.

... x - √30 = 0 . . . . the first factor is zero

... x = √30

... x + √30 = 0 . . . . the second factor is zero

... x = -√30

The solutions are . . .

... x = ±√30 . . . . . matches your 3rd choice

klasskru [66]3 years ago

4 0

Answer: C

Step-by-step explanation: hope it helps :)

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Solve by completing the square.

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Answer:

x^2 -8x -5 = -3

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We complete the square by:

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x^2 -8x = 2

2) Dividing the equation by the coefficient of X²

The coefficient of x is 1 so we don't do anything

3) Now here's the "completing the square" stage in which we:

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Step-by-step explanation:

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lapo4ka [179]

Answer:

a) 388.03

b) 148.49

c) π/8

Step-by-step explanation:

Find the diagram attached

Let the opposite side be y

Given

a) Hypotenuse = 420

theta = 3π/8 rad

theta = 3(180)/8

theta = 67.5degrees

Using the SOH CAH TOA identity

sin theta = opposite/hypotenuse

sin 67.5 = y/420

x = 420sin67.5

x = 420(0.9238)

x = 388.03

Hence the length of the side opposite to the given angle is 388.03

b) Hypotenuse = 420

theta = 3π/8 rad

theta = 3(180)/8

theta = 67.5degrees

Using the SOH CAH TOA identity

cos theta = adjacent/hypotenuse

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Let the measure of the unknown angle be z

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z = π/8

Hence the measure of the other acute angle is π/8

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