A scraper removes floatable solids.

Some students of class 7 were taken for an educational trip to Waste water treatment plant .The teacher explained the process of water treatment. Identify the correct order of the process.

Step I:The liquid material is passed through sedimentation tank where solid waste like faecal matter, sand, grit settles down.

Step II:This solid matter is then removed with the help of a scrapper. This is the sludge.

Step III: Waste water is passed through bar screens to remove big objects like cans, sticks, rags etc.

Step IV: A skimmer removes the floatable solids like oil, grease etc.

Step V: Air is pumped into clarified water to help aerobic bacteria to grow. The bacteria then consume the unwanted matter still present in clarified water.

Step VI: The clear water so obtained is called clarified water.

Step VII:The suspended microbes settle at the bottom & the water is removed from the top.

X = -5 can this be expressed as a linear equation in two variables?

True

False