Factorise: 4x squared - 9y squared

What is the effect on the graph of the function f(x) = x2 when f(x) is changed to f(x) − 4?

£100.80 divided by 14 equals 7.2 how would we put this as money

Mr. jones determined that the equation y = 98 - 16/5 x could be used to predict his students' unit test scores, based on the number of days, x, a student was absent during the unit. what was the meaning of the y-intercept of the function? (by the way the 16/5 is a )