x, 20%, __________;y, 10%, __________;780, 1, 2___________________________.

(1+20%) x(1+20%) x- (1-10%) y=780(1-10%) y

( -)200,20%,10%,780.,?

=200 =780 20020%10%780 :.=(1+20%=(110%

xy xy200(1+20%) x(1-10%) y780xy=200 (1+20%)x(1 10%) = 78020020%10%780

xy =1+20%x =110%y : 20001800

0.510.70.43540

0.5xx0.7y0.4yx,y0.5x+0.7y=35x+0.4y=40 0.510.70.43540

xy

1 ,100,()81%,87.5%,75%,?

10..

2,36,2,2.5;2,3.,?

xy xy200780xy =78020020%10%780

4.4,6,2.?x,y,

.

4.4,6,2.?x,y, ()