若x+y=3x+3y=1则3x^2+12xy+12y^2等于多少

已知:x+y=0.2 x+3y=1 求3x^2+12xy+12y^2的值!要求不直接算出x和y的值,
2024-11-22 14:58:00
推荐回答(1个)
回答1:

x+y=0.2
x+3y=1
两式相加,得2x+4y=1.2
x+2y=0.6
3x^2+12xy+12y^2
=3(x^2+4xy+4y^2)
=3(x+2y)^2
=3*0.6^2
=1.08