Linear equation has a degree of 1, that means the maximum power of a variable in a linear equation/expression should be 1. if an equation doesn't satisfy this condition then it's not a linear equation.
So, by Observing the choices, we get to the conclusion that the one which isn't a linear equation is B
Here, the variables have greater powers tham one, and degree is 3. so it's the required Answer ~
Linear eqautions can not contain exponents in them. B has x to the power of 3 and y to the power of 2, ruling it out to be a linear equation. I hope this helps! :)
Round up: 60*1 = $60. Everytime you add $0.99, you subtract off a penny, so you will subtract off 60 pennies. 60 cents from the original answer, so 60-0.6=59.4.