x=-3,y的绝对值=5,z+3=0,求xy-yz+xz的值
问题描述:
x=-3,y的绝对值=5,z+3=0,求xy-yz+xz的值
答
y的绝对值=5,z+3=0所以y=5或y=-5,z=-3
当y=5时,xy-yz+xz=(-3)x5-5x(-3)+(-3)x(-3)=9
当y=-5时,xy-yz+xz=(-3)x(-5)-(-5)x(-3)+(-3)x(-3)=9