1. S OLVING E QUATIONS ! { WITH DECIMALS } U2L11 PS2 Solve single- and multi-step word problems involving operations with fractions and decimals and verify the solutions DO NOW: JJ is baking a cake. He wants to double the recipe so he has enough to share with the whole class. The recipe calls for 3 ½ cups of flour. First he added 1 ¾ cup and later he added 2 ½ cups. How many more cups of flour does he need? Planner: Hw p. 216 - 217 #9, 22, 23, 38, 40, 41

2. W HAT IS AN EQUATION ? Equation: a mathematical statement that two things are equal. It consists of two expressions, one on each side of an 'equals' sign. We know the left side and right side are equal Equations are like a balance scale

3. S OLVING AN EQUATION -- T ERMINOLOGY “Solving the equation” = The process of finding the value of the variables We say "solve for x" - meaning solve the equation to find the value of the unknown number x that makes the statement true In order to “solve for x”, we must “isolate the variable” (We need to get x alone on one side of the equal sign) Goal is to end up with x = something

4. H OW TO SOLVE EQUATIONS To get x alone– UNDO every operation that is happening to x UNDO  perform the opposite operation Do PEMDAS in reverse! (add/subtract first, then multiply/divide, etc) Whatever you do to an equation, do the S A M E thing to B O T H sides of that equation! Keep the scale balanced Example: x + 4.5 = 23.2 -4.5 -4.5 x = 18.7 4.5 is being added to x, so we UNDO the operation by doing the opposite operation Subtract 4.5 from BOTH SIDES If I have x = something, I’m done

5. A NOTHER EXAMPLE 2x – 12.4 = 32.4 +12.4 +12.4 2x = 44.8 2 2 x = 22.4 12.4 is being subtracted from x, so we UNDO it by ADDING 12.4 to both sides We don’t quite have x = something so we have more work to do X is being multiplied by 2, so we UNDO it by DIVIDING both sides by 2 X = something, we are done!

6. I CAN SOLVE EQUATIONS … "You gotta do the same thing on both sides“ Examples: p + 8 = 14.1 n + 4.7 = −4.7 x = −7 1.2 n + 3.9 = 0.7 −6.3n = −8.19 32.663 = p + 11.363

7. A SSIGNMENT P. 216- 217 #9, 22, 23, 38, 40, 41