Equation 2 is the only one possible to be linear. All of the other answers have an exponents. For instance, say you have y=x^3. For 1, it is 1*1*1. (1,1). For 2, it is 2*2*2. (2,8). For 3, 3*3*3. (3,27) It escalates into a curve and is non-linear.
A=automobile S=SUV 0.4A+A=98 (to change a percent to a decimal you move the decimal point two places to the right) 1.4A=98 (I combined like terms) A=70 (divided each side by 1.4)