Before you can use the distance, rate, and time formula, D=RT, you need to make sure that your units for the distance and time are the same units as your rate. If they aren’t, you’ll need to change them so you’re working with the same units.

Read MoreThe main idea in inverse variation is that as one variable increases the other variable decreases, which means that if x is increasing y is decreasing, and if x is decreasing y is increasing. The number k is a constant so it’s always the same number throughout the inverse variation problem.

Read MoreLaws of logarithms (or laws of logs) include product, quotient, and power rules for logarithms, as well as the general rule for logs (and the change of base formula we’ll cover in the next lesson), can all be used together, in any combination, in order to solve log problems.

Read MoreTwo-step problems are problems in which you need to not only solve an equation for the value of a variable, but then also use the solution to evaluate some other expression that depends on that same variable.

Read MoreThe domain is all x-values or inputs of a function and the range is all y-values or outputs of a function. When looking at a graph, the domain is all the values of the graph from left to right. The range is all the values of the graph from down to up.

Read MoreIt’s helpful to think about multiples and divisibility as two parts of the same idea. We know that 10 is “divisible” by 5 because when we do the division 10/5, the result 2 is a whole number. It’s the fact that the result is a whole number that proves that 10 is divisible by 5.

Read MoreYou can always evaluate logs using the general log rule, but sometimes, depending on the value of the base and the argument, simplifying the exponential expression can be a little tricky.

Read MoreThere are three ways to solve systems of linear equations: substitution, elimination, and graphing. Substitution will have you substitute one equation into the other; elimination will have you add or subtract the equations to eliminate a variable; graphing will have you sketch both curves to visually find the points of intersection.

Read MoreTo add rational expressions, you need to find a common denominator, just like when you add fractions in which the numerator and denominator are just numbers. The difference is that finding the common denominator of rational expressions can be more complicated because their denominators can include variables.

Read MoreMultiplying multivariable polynomials (polynomials with two or more different variables) is very similar to multiplying single-variable polynomials (those that have just one variable). You’ll just need to be careful about combining like terms.

Read MoreThe zero theorem allows you to solve for the roots of a polynomial function. Just factor the polynomial, set it equal to 0, and solve for the variable to find the roots.

Read MoreUniform motion explains the distance of an object when it travels at a constant speed, the rate, over a period of time. To compare different rates, times, and distances you can use subscripts to keep track of which pieces go with which equation.

Read MoreWe’ll solve for the variable in a radical equation by isolating the radical, squaring both sides and then using inverse operations.

Read MoreThe “1,089 rule” isn’t really a rule at all, it’s more like a fun thing that happens with numbers that you can explain with algebra.

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