`A=312^2-53^2-35^2-53.70`
`A=312^2-(35^2+2.35.53+53^2)`
`A=312^2-(35+53)^2`
`A=312^2-88^2`
`A=(312-88)(312+88)`
`A=224.400`
`A=89600`
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`B=47^2-68^2+32^2-53^2`
`B=(47^2-53^2)-(68^2-32^2)`
`B=(47-53)(47+53)-(68-32)(68+32)`
`B=-6.100-36.100`
`B=100.(-6-36)`
`B=-42.100`
`B=-4200`