Question

pls answer this pleaseeee i beg you its urgent

Answer 1

Given

If 9x² + 25y² = 181 and xy = -6, find the value of 3x + 5y

Solution

• 9x² + 25y² = 181
• xy = - 6

★ Applying identity :

(a + b)² = a² + b² + 2ab

➟ (3x + 5y)² = (3x)² + (5y)² + 2*3x*5y

➟ (3x + 5y)² = (3x)² + (5y)² + 2*3x*5y

➟ (3x + 5y)²= 9x² + 25y² + 30xy

➟ (3x + 5y)² = 181 + 30(-6)

➟ (3x + 5y)² = 181 - 180

➟ (3x + 5y)² = 1

➟ (3x + 5y) = √1

➟ (3x + 5y) = 1

Answer 2

Given:

9x² + 25y² = 181 and xy = -6

To find:

Find the value of 3x + 5y

Formula used:

(a + b ) = a² + b² + 2ab

Solution:

(3x + 5y)² = (3x)² + (5y)² + 2 × 3x × 5y

➟ (3x + 5y)² = (3x)² + (5y)² + 2 × 3x × 5y

➟ (3x + 5y)²= 9x² + 25y² + 30xy

➟ (3x + 5y)² = 181 + 30(-6)

➟ (3x + 5y)² = 181 + (-180)

➟ (3x + 5y)² = 1

➟ (3x + 5y) = √1

➟ (3x + 5y) = 1

Hence, the value of 3x + 5y is 1.