it is Arithmetic because if you subtract 12 from 40 you'll get 28 , same for the others. but if you get the common ratio by dividing 40/12 which is 3.333... it's doent work for the sequence
in the linear equation the greatest power of the variables is 1 for example:2X+4 this is a linearequationasthegreatestpowerofthevariableX is 1also by drawing it in a graph you will obtain a straight line
while in the quadratic equation the greatestpoweris2for instance:X^2+4X-3 this is a QuadraticequationbecausethegreatestpowerofthevariableX is 2also by drawing it on a graph you will obtain a parabola which is a curve "an upward curve or downward curve"
