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Let m = 2x + 3. Which equation is equivalent to (2x + 3)² - 14x - 21 = -6 in terms of m? Choose 1 answer:

(A) m² - 7m+6=0
(B) m² + 7m +6=0
(C) m² + 7m - 15 = 0
(D) m² - 7m - 15 = 0​

User AGML
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1 Answer

2 votes

Answer:

Heya

Explanation:

To find the equation that is equivalent to (2x + 3)² - 14x - 21 = -6 in terms of m, we need to substitute m with 2x + 3.

Let's substitute m = 2x + 3 into the equation:

(2x + 3)² - 14x - 21 = -6

Expanding the square of (2x + 3):

(4x² + 12x + 9) - 14x - 21 = -6

Simplifying the equation:

4x² - 2x - 18 = -6

Bringing all terms to one side:

4x² - 2x - 18 + 6 = 0

Combining like terms:

4x² - 2x - 12 = 0

Now we have the equation in terms of x. To find the equation in terms of m, we need to substitute back m = 2x + 3.

Let's substitute m = 2x + 3 into the equation:

4(2x + 3)² - 2(2x + 3) - 12 = 0

Expanding the square of (2x + 3):

4(4x² + 12x + 9) - 4x - 6 - 12 = 0

Simplifying the equation:

16x² + 48x + 36 - 4x - 6 - 12 = 0

Combining like terms:

16x² + 44x + 18 = 0

Now we have the equation in terms of m. Simplifying further, we get:

m² + 7m - 15 = 0

Therefore, the equivalent equation in terms of m is (C) m² + 7m - 15 = 0.

User AshOoO
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