I need help with 7 and 8, Round and/or estimate then add (nearest hundred) for both attachment below

Simone claims the initial value and y-intercept are the same thing on a graph. is she correct? if you know that a line has a slope of and a y-intercept of 7, what is the equation for that line in slope-intercept form?

There are 15 plates and each plate is either 7 or 12 inches diameter. which systems of equations do you use to find the number of 7 inch plates, x and 12 inch plates, y

Which basic geometric term has no width, no length, and no thickness? line b. point c. angle d. plane