答案
解:∵|x|=3,|y|=5,
∴x=±3,y=±5,
∵x<y,
∴x=3,y=5或x=-3,y=5,
x=3,y=5时,x-y+2xy=3-5+2×3×5=-2+30=28,
x=-3,y=5时,x-y+2xy=-3-5+2×(-3)×5=-8-30=-38.
解:∵|x|=3,|y|=5,
∴x=±3,y=±5,
∵x<y,
∴x=3,y=5或x=-3,y=5,
x=3,y=5时,x-y+2xy=3-5+2×3×5=-2+30=28,
x=-3,y=5时,x-y+2xy=-3-5+2×(-3)×5=-8-30=-38.