What property is (−6.8+(−5.1))+6.2=(−5.1+(−6.8))+6. need asap

Agreeting card company can produce a box of cards for $7.50. if the initial investment by the company was $50,000, how many boxes of cards must be produced before the average cost per box falls to $10.50?

Which of the following is the equation that says that the product of a number and ten is equal to 20 percent of that number ? a) 10n= 2.0n b) 10+n=.20n c) n+ .20n=10 d) 10n=0.20n

Aline has a slope of 1/4 and passes through point (0.4,-1/2). what is the value of the y-intercept?