A two-step equation needs two inverse operations to solve, like . To solve two-step equations, first undo the adding or subtracting, then undo the multiplying or dividing. Do each step to both sides: becomes , so . Before this lesson: You should know how to solve one-step equations and how to use the order of…
A one-step equation takes just one operation to solve. To solve one-step equations, undo the operation on the variable with its inverse: subtract to undo adding, add to undo subtracting, divide to undo multiplying, and multiply to undo dividing. Do the same thing to both sides. For example, gives . Before this lesson: You should…
The distributive property says that multiplying a number by a sum is the same as multiplying it by each part and then adding: . For example, . You use the distributive property to remove parentheses and simplify expressions. Before this lesson: You should know how to combine like terms and how to multiply negative numbers….
Combining like terms means adding or subtracting terms that have the same variable part. Like terms have the same variables raised to the same powers, such as and . To combine them, add their coefficients and keep the variable part: . Before this lesson: You should know what the terms of an expression are and…
An algebraic expression is a math phrase made of numbers, variables and operations, like or . It has no equals sign. To evaluate an algebraic expression, replace each variable with its value and follow the order of operations. To write one, turn the words of a problem into symbols. Before this lesson: You should know…
A variable is a letter, like or , that stands for a number. Variables in math let you write a rule that works for many numbers, or hold the place of a number you don’t know yet. In , the letter is the variable. If , then . Before this lesson: You should know the…
