linear equations word problems .

Which is the graph of f(x) = (4)x? image for option 1 image for option 2 image for option 3 image for option 4

How many of the 250 grandparents in the population would you expect to prefer online shopping with merchant a? merchant a: 4 merchant b: 6 merchant c: 2 merchant d: 3 other: 5 none: 5 answer choices: a.about 4 b.about 8 c.about 40 d.about 21

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?