[" 57.Twenty meters of wire is available for fencing off a "],[" flower-bed in the form of a circular sector.Then the "],[" maximum area (in sq."m" ) of the flower-bed,is: "],[qquad " [JEEMAIN "2017]]

Explanation

`3x-7y^2+3xyz=3(2)-7(-4)^2+3(2)(-4)(1)`

`=6-7xx16-6xx4`

`=6-112-24`

`=6-136`

`=130`