It would be sonar i think
Well its all due to Green house gasses produced through factories and automobiles, with the abundance of the world, driving, fly, and burning gas and oil on the whim we are playing a major role in this and unless a new technology that can surpass oil and natural gas we are slowly killing ourselves and the world.
subtract 8 from both sides leaving
combine -2x+-8x =-10x
divide both sides by ten
Challenges for growing crops are you don't know if it will be successful, you have to have enough water, the dirt has to be fertile, and the weather may affect how the plant grows.
