Question

Which equation represents a linear function?

Equation 1: y3 = 2x + 1
Equation 2: y = 3x + 1
Equation 3: y = 5x2 − 1
Equation 4: y = 4x4 − 1

Answer 1

To have a linear function you must have only variables to the first power. You can't have any exponents on variables other than 1, you can't have products of variable, you can't have variables in the denominator or in a square root or any other root.

Answer 2

so what do I have to do.

Answer 3

Look at each equation in the choices.
If you see an exponent other than 1 on x or y, it is not linear.
For the function to be linear you need to have x and y, each one alone or just multiplied by a number, but with no exponent on the x or y.