Question

. If 9x^2 + 25y^2 = 46 and xy = -1. find 3x+5y

Answer 1

Answer:

(3x+5y)²= 46- 30=16

3x+5y=4

Answer 2

Step-by-step explanation:

$(3x + 5x)^{2} = 9 {x}^{2} + 25 {y}^{2} + 2 \times 3x \times 5y \\ (3x + 5y) ^{2} = 9 {x}^{2} + 25 {y}^{2} - 30 \\ (3x + 5y) ^{2} = 46 - 30 \\ (3x + 5y) ^{2} = 16 \\ 3x + 5y = \sqrt{16} \\ 3x + 5y = 4$