When x = 2, y = 50 and when x = 4, y = 100. which direct variation equation can be used to model this function?

xy = 100
xy = 400
y = 25x
y = 100x

Find the x-intercept and y-intercept of the line. 3x + 5y = −15

Which of the statements about the graph of the function y = 2x are true? check all of the boxes that apply. the domain is all real numbers x because the exponent of 2 can be any real number when the x-values increases by 1 unit, the y-value multiplies by 2. the y-intercept is (0, 1). the graph never goes below the x-axis because powers of 2 are never negative. the range is all real numbers.

I'm confused on this could anyone me and show me what i need to do to solve it.