Question

Oblicz wartość wyrażenia:
x* - 2y*+ xy dla
a] x=2 y= -5
b] x= - 1/2 y= 2/3
c]x= -2 1/2 y= -1 1/4

/-ułamek
*-potega {2}

Answer 1

A)x=2     y=-5
2²-2x(-5)²+2x(-5)=4-2x25-10=4-50-10= - 56
b)
x=-1/2         y=2/3
(-1/2)²-2x(2/3)²+(-1/2)x(2/3)=1/4-2x4/9+(-2/6)=1/4-8/9-2/6= 9/36-56/36-12/36= -59
c)
x= -2 1/2      y=-1 1/4
(-2 1/2)²-2x(-1 1/4)²+(-2 1/2)x(-1 1/4)= (-5/2)²-2x(-5/4)²+(-5/2)x(-5/4)= 25/4-2x25/16+25/8=50/8-25/8+25/8=50/8=6 2/8=6 1/4