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Find a value for m and n to make a true statement.

a) mx^2 - 36 = (3x + 6)(3x - 6)
b) (mx + ny)^2 = 4x^2 + 12xy + 9y^2

User Faire
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1 Answer

2 votes

Answer:

Correct answer: a) m = 9 ; b) m = 2 and n = 3

Explanation:

Given:

a) m x² - 36 = (3 x + 6) (3 x - 6) ⇒ m = ?

b) (m x + n y)² = 4 x² + 12 x y + 9 y² ⇒ m, n = ?

a) m x² - 36 (3 x + 6) (3 x - 6)

The right side of the equation is the difference of the square, so we will present the left side in the same way:

(√m x)² - 6² = (3 x + 6) (3 x - 6)

(√m x + 6) (√m x - 6) = (3 x + 6) (3 x - 6)

√m = 3 /² when we square both sides of the equation we get:

m = 9

b)

(m x + n y)² = 4 x² + 12 x y + 9 y²

The left side of the equation is the complete square of the binomial, so we will present the right side in the same way:

(m x + n y)² = (2 x)² + 2 · 2 x · 3 y + (3 y)² = (2 x + 3 y)²

(m x + n y)² = (2 x + 3 y)² ⇒

m = 2 and n = 3

God is with you!!!

User Emre AYDIN
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