Question

tell me the answer of 7th number question​

Answer 1

solution:

here,

9x^2 + 25y^2 = 181

xy= -6

3x+5y = ?

now,

9x^2 + 25y^2 = 181

(3x)^2 + (5y)^2 = 181

(3x + 5y)^2 -2×3x×5y = 181

(3x + 5y )^2 - 2× 3 × 5 × (-6) = 181

(3x + 5y)^2 + 180 = 181

(3x + 5y)^2 = 181 - 180

(3x + 5y)^2 = 1

3x + 5y = 1 #