Which equation is a linear equation in one variable

Question

9 + 2 = 11

4x^2 - 2x = 5

2x+y=8

3x-12=4x

Answer 1

1. Constants appear as numbers -- like 9, 2, 11
2. Variables use a letter -- like x, y, z
3. A linear equation has an exponent of 1 (which does not show) for each variable that appears.

Important note: x¹ = x

Apply those rules:

9 + 2 = 11 Only constants; no variables

4x^2 - 2x = 5 An exponent of variable x is not 1 (an exponent of 2 appears)

2x+y=8 Linear equation (exponents of 1) in two variables

3x-12=4x Linear equation (exponent of x is 1) in one variable (that is, x)