Lesson 3: How to Write Equations

Content Standards and Objectives 6.EE.7 (CCSS.6.EE.B.7) Solve real world and mathematical problems by writing and solving equations of the form x + p = q and px= q for cases in which p, q, and x are all nonnegative rational numbers.

Sally sold cupcakes for a school trip x = the number of cupcakes sold Sally sold cupcakes for a school trip. Each cupcake sold for $2.00 Now, we have an expression 2x In the Previous Lesson

Writing and Solving Equations Sally sold cupcakes for $2.00 each for a school trip. She made $50. 2x = 50

Writing and Solving Equations 2x = 50 2x/2 = 50/2 x = 25

Checking Answers Using Substitution 2x = 50 2 ● (25) = = 50

Now Try to Write and Solve an Equation from a Real World Problem On Your Own

Lucy bought a birthday cake for her mother. She spent $27 on the cake and also bought some decorations for the party. If she spent a total of $100, how much money did Lucy spend on decorations?

Solving Equations Let x = the amount of the decorations x + 27 = 100 x = 100 – 27 x = 73

Checking Answers Using Substitution x + 27 = 100 (73) + 27 = = 100