Which equation represents a direct linear variation?
a. y=x to the second power which mean like a little 2
b. y=2/5x
c. y=1/x
d. y=x+3

Ametalworker has a metal alloy that is 30? % copper and another alloy that is 55? % copper. how many kilograms of each alloy should the metalworker combine to create 90 kg of a 50? % copper? alloy?

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

Which of the following are accepted without proof in a logical system? check all that apply.