Tutoring statistics, regression is an important topic. The tutor defines multiple linear regression.

Simple linear regression models the dependent variable by a linear connection to the independent:

y = a + bx

Multiple linear regression models the dependent variable by a linear connection across several independent variables:

y = a + b₁x₁ + b₂x₂ + b₃x₃ + ….

Source:

Harnett, Donald L. and James L. Murphy. Statistical Analysis for Business and Economics. Don Mills: Addison-Wesley, 1986.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.