已知x和y满足2x+3y=5,则当x=4时,代数式3(xXx)+12xy+(yXy)的值是( )

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已知x和y满足2x+3y=5,则当x=4时,代数式3(xXx)+12xy+(yXy)的值是( )
已知x和y满足2x+3y=5,则当x=4时,代数式3(xXx)+12xy+(yXy)的值是( )

已知x和y满足2x+3y=5,则当x=4时,代数式3(xXx)+12xy+(yXy)的值是( )
2x+3y=5
3y=5-2x
y=(5-2x)/3
3x^2+12xy+y^2
=3x^2+12x(5-2x)/3+(5-2x)^2/9
x=4时
=48-48+1
=1