# sum of differences   7 videos

• #### Sum of Digits

##### AlgebraWord Problems Using Systems of Equations

How to solve a problem when asked to switch the digits of a 2-digit number.

sum digits word problem
• #### Difference of Perfect Squares

##### AlgebraFactoring

How to recognize and factor a binomial that is the difference of perfect squares.

perfect square coefficients binomial
• #### Multiplying Polynomials: Special Cases

##### AlgebraPolynomials

How to recognize special products of polynomials.

perfect square trinomial difference of perfect squares binomial
• #### Factoring: Special Cases Part I

##### AlgebraFactoring

How to factor perfect square trinomials.

FOIL difference of perfect squares perfect square trinomial
• #### Additive and Multiplicative Inverses

##### AlgebraPre-Algebra

How to find additive and multiplicative inverses.

additive inverse multiplicative inverse product sum
• #### Mixture Problems

##### AlgebraWord Problems Using Systems of Equations

How to solve word problems when mixing two quantities with different prices.

amount price mixture word problem
• #### Percent Concentrations

##### AlgebraWord Problems Using Systems of Equations

How to solve word problems about mixing two liquids with different percent concentrations.

percent concentration mixture