Question

x+2y=a;x-2y=b;el valor de xy

Answer 1

x+2y=a
x=a-2y   ............(1)

x-2y=b
x=b+2y............(2)

(1)=(2)
a-2y=b+2y
(a-b)=2y+2y

(a-b)/4= y   ...(3)

de (1)
x=a-2y
x=a-[ 2(a-b)/4]
x=a-(a/2)+(b/2)=(a/2)+(b/2)=(1/2)(a+b)
x=(1/2)(a+b) ...........(4)

nos piden xy  de (3)y(4)
xy=(a+b)/2 * (a-b) /4=(a+b)(a-b)/8=(a²-b²)/8
rpta :

xy=(a²-b²)/8

Answer 2

Respuesta:

nose ni siquira

Explicación paso a paso: