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3 years ago

9 more than two-sevenths a number is 45. What is the number? Also, show an explanation.

Mathematics

1 answer:

photoshop1234 [79]3 years ago

3 0

Answer:

x=126

Step-by-step explanation:

let 'x' represent the unknown number

(2/7)x + 9 = 45

Subtract 9 from both sides

2/7x=36

Because the fraction is being multiplied by 'x' we can multiply both sides by its reciprocal (because a fraction multiplied by its reciprocal is 1 which would 'eliminate' it from the left side therefore isolating 'x').

x=126

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Step-by-step explanation:

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3 years ago

Factor the polynomial x2 + 18x + 81 as the product of two binomials

hram777 [196]

Answer:

$(x+9)^2$

Step-by-step explanation:

We have the polynomial x^2 + 18x + 81 and are being asked to factor this into two binomials.

A rule that I follow is what two numbers multiplied make c (in this case 81) and when added make b (in this case is 18).

So what two numbers when :

A. Multiplied make 81

B. Added make 18

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Now that we have the answer, we can put it into binomials.

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3 years ago

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Step-by-step explanation:

Let's calculate the acute angle at the base of the triangle:

180° - 90° - 40° = 50°

Find side x:

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3 years ago

Solve x^2 + 4x + 8 = 0

Mkey [24]

Answer:

x = -2 + 2 i or x = -2 - 2 i

Step-by-step explanation:

Solve for x:

x^2 + 4 x + 8 = 0

Subtract 8 from both sides:

x^2 + 4 x = -8

Add 4 to both sides:

x^2 + 4 x + 4 = -4

Write the left hand side as a square:

(x + 2)^2 = -4

Take the square root of both sides:

x + 2 = 2 i or x + 2 = -2 i

Subtract 2 from both sides:

x = -2 + 2 i or x + 2 = -2 i

Subtract 2 from both sides:

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8 0

3 years ago