Respuesta :

(Cross Multiply)2a+2b=a-b
a=-3b
if b=1; a=-3
correct answer is -3..
Good Luck..
1=a+b. 2=a-b a= 2+b 1=2+b+b. a=2-1/2=3/2 -1=2b b=-1/2 a/b= (3/2)/(-1/2) = (3/2)(-2/1) =-3