已知:x+y=0.2,x+3y=1,则3x2+12xy+12y2的值为_.
问题描述:
已知:x+y=0.2,x+3y=1,则3x2+12xy+12y2的值为______.
答
∵x+y=0.2①,x+3y=1②,
∴①+②得:2x+4y=1.2,
∴x+2y=0.6,
∴3x2+12xy+12y2
=3(x2+4xy+4y2)
=3(x+2y)2
=3×0.62
=1.08.
故答案为:1.08.