Question

14. If 5x - 2y = 7 and xy = 2, find the value of (5x +
2y)whole square

Answer 1

Answer:

129

Step-by-step explanation:

5x-2y=7

now squaring both sides and applyling a-b Ka whole square formula

(5x-2y)^2=(5x)^2+(2y)^2-2(5x)(2y)

substitute the values

(7)^2=(5x)^2+(2y)^2-2(10)(xy)

49=(5x)^2+(2y)^2-20(2)

49=(5x)^2+(2y)^2-40

49+40=(5x)^2+(2y)^2

89=(5x)^2+(2y)^2

now (5x+2y)^2=(5x)^2+(2y)^2+2(5x)(2y)

substitute the values

(5x+2y)^2=89+2(5x)(2y)

(5x+2y)^2=89+20(2)

(5x-2y)^2=129

hope it helps:)))))