You start a new business. The location costs 100,000 to rent for one year. The items cost you $12 to make. You sell the items for
$20 each. How many items do you have to sell to break-even
(get out of debt, or make back what you spent) ?

-6 is the correct option from the above given options

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this

3x + 4y -25 =0 represents the amount of change sianna should recieve