What is a positive proportion function? What is an inverse proportion function? What is a linear function

What is a positive proportion function? What is an inverse proportion function? What is a linear function

Generally, a function of the form y = KX (k is a constant, K ≠ 0) is called a positive proportional function, where k is called a proportional coefficient. For example, y = 3x; y = - 0.5x
Generally, a function of the form y = KX + B (k, B are constants, K ≠ 0) is called a first-order function. When B = 0, y = KX + B is y = KX, so the positive proportional function is a special first-order function. For example, y = 8x-7; y = - 9x
Generally, a function of the form y = K / X (k is a constant, K ≠ 0) is called an inverse proportional function, where x is an independent variable, y is a function, and the value range of the independent variable x is all real numbers not equal to 0. For example, y = 453 / X; y = - 89 / X