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2 years ago

A student says that if 5x2 = 20, then x must be

Mathematics

1 answer:

lutik1710 [3]2 years ago

4 0

Answer:

I agree with the student's answer. "x" cannot be -2 because then it would make -20 which is not equal to 20:

5(-2)(2) = ?

-10 x 2 = ?

? = -20

-20 ≠ 20

Step-by-step explanation:

Justificaiton:

5(x)(2) = 20

10(x) = 20

10/10(x) = 20/10

x = 2

Second Justification:

5(x)(2) = 20

5/5(x)(2) = 20/5

2x = 4

2x/2 = 4/2

x = 2

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3 years ago

6 numbers form an arithmetic sequence with a common difference of 4. THe sum of these numbers equals 12. What are the 6 numbers.

frutty [35]

Answer: See explanation

Step-by-step explanation:

We will use the formula for an arithmetic sequence which will be:

a + (n - 1)d

where a = unknown

n = 6

d = 4

We then slot them into the formula

a + (6 - 1)4 = 12

a + 5(4) = 12

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a = 12 - 20

a = -8

The 6 numbers are

1st term = -8

2nd term = -8 + 4 = -4

3rd term = -4 + 4 = 0

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3 years ago

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Alex Ar [27]

Answer:

Step-by-step explanation:

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3 years ago

The points (a,5) and (9,b) are on the circle x^2+ y^2= 125.

Aneli [31]

Answer:

a = 10

b = 6.633

Step-by-step explanation:

x²+ y²= 125.

In this equation, the value of x and y represent the coordinates of x and y respectively of point on which the circle passes.

x²+ y²= 125

a² + 5² = 125

a² + 25 = 125

a² = 125-25

a² = 100

a = √100 = 10

(9,b)

x²+ y²= 125

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2 years ago

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GalinKa [24]

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Step-by-step explanation:

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3 years ago