1 / 13

Solving Equations by Adding or Subtracting Decimals

Solving Equations by Adding or Subtracting Decimals. PRE-ALGEBRA LESSON 3-5. (For help, go to Skills Handbook page 730.). Simplify. 1. 2.8 + 7.06 2. 0.65 + 1.8 3. 4.52 – 2.48 4. 3.7 – 0.62. Check Skills You’ll Need. 3-5. Solving Equations by Adding or Subtracting Decimals.

trynt
Download Presentation

Solving Equations by Adding or Subtracting Decimals

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Solving Equations by Adding or Subtracting Decimals PRE-ALGEBRA LESSON 3-5 (For help, go to Skills Handbook page 730.) Simplify. 1. 2.8 + 7.06 2. 0.65 + 1.8 3. 4.52 – 2.48 4. 3.7 – 0.62 Check Skills You’ll Need 3-5

  2. Solving Equations by Adding or Subtracting Decimals PRE-ALGEBRA LESSON 3-5 Solutions 1. 2.80 2. 0.65 + 7.06 + 1.80 9.86 2.45 3. 4.52 4. 3.70 – 2.48 – 0.62 2.04 3.08 3-5

  3. 6.8 – 6.8 + p = –9.7 – 6.8 Subtract 6.8 from each side. p = –16.5 Simplify. Check 6.8 + p = –9.7 Replace p with –16.5. 6.8 + (–16.5) –9.7 –9.7 = –9.7 Solving Equations by Adding or Subtracting Decimals PRE-ALGEBRA LESSON 3-5 Solve 6.8 + p = –9.7. 6.8 + p = –9.7 Quick Check 3-5

  4. x + 8.75 – 8.75 = 14.5 – 8.75 Subtract 8.75 from each side. x = 5.75 Simplify. Solving Equations by Adding or Subtracting Decimals PRE-ALGEBRA LESSON 3-5 Ping has a board that is 14.5 ft long. She saws off a piece that is 8.75 ft long. Use the diagram below to find the length of the piece that is left. x + 8.75 = 14.5 The length of the piece that is left is 5.75 ft. Quick Check 3-5

  5. –23.34 + 16.99 = q – 16.99 + 16.99 Add 16.99 to each side. –6.35 = q Simplify. Solving Equations by Adding or Subtracting Decimals PRE-ALGEBRA LESSON 3-5 Solve –23.34 = q – 16.99. –23.34 = q – 16.99 Quick Check 3-5

  6. Words previous balance minus check is new balance Let p = previous balance. Equation p – $49.98 = $169.45   p – 49.98 + 49.98 = 169.45 + 49.98 Add 49.98 to each side. p = 219.43 Simplify. Solving Equations by Adding or Subtracting Decimals PRE-ALGEBRA LESSON 3-5 Quick Check Alejandro wrote a check for $49.98. His new account balance is $169.45. What was his previous balance? p – 49.98 = 169.45 Alejandro had $219.43 in his account before he wrote the check. 3-5

  7. Solving Equations by Adding or Subtracting Decimals PRE-ALGEBRA LESSON 3-5 Solve each equation. 1.a + 10 = 7.9 2. –1.01 = c – 9 3.s – (–2.6) = 1.6 4. 3.02 + d = 2.91 5. –23.7 = 13.3 + g – 2.1 7.99 – 1 – 0.11 – 37 3-5

  8. daily milk consumption numberof days Words times is 250 gallons Let x = number of days. 250 x Equation • = 85.8 Solving Equations by Multiplying or Dividing Decimals PRE-ALGEBRA LESSON 3-6 Every day the school cafeteria uses about 85.8 gallons of milk. About how many days will it take for the cafeteria to use the 250 gallons in the refrigerator? 3-6

  9. 85.8x 85.8 250 85.8 = Divide each side by 85.8. x = 2.914 . . . Simplify. x 3 Round to the nearest whole number. Solving Equations by Multiplying or Dividing Decimals PRE-ALGEBRA LESSON 3-6 (continued) 85.8x = 250 The school will take about 3 days to use 250 gallons of milk. Quick Check 3-6

  10. –37.5 = Multiply each side by –1.2. –37.5(–1.2) = (–1.2) 45 = c Simplify. c –1.2 c –1.2 c –1.2 Solving Equations by Multiplying or Dividing Decimals PRE-ALGEBRA LESSON 3-6 Solve –37.5 = . Quick Check 3-6

  11. a = h n h n h 15 0.133 = Replace a with 0.133 and n with 15. Solving Equations by Multiplying or Dividing Decimals PRE-ALGEBRA LESSON 3-6 A little league player was at bat 15 times and had a batting average of 0.133 (rounded to the nearest thousandth). The batting average formula is a = , where a is the batting average, h is the number of hits, and n is the number of times at bat. Use the formula to find the number of hits she made. 3-6

  12. 0.133(15) = (15) Multiply each side by 15. Simplify. 1.995 = h 2 h Since h (hits) represents an integer, round to the nearest integer. h 15 Solving Equations by Multiplying or Dividing Decimals PRE-ALGEBRA LESSON 3-6 (continued) The little league player made 2 hits. Quick Check 3-6

  13. p –2.5 Solving Equations by Multiplying or Dividing Decimals PRE-ALGEBRA LESSON 3-6 Solve each equation. 1. 9b = –30.6 2. –10.8 = 3. 2.45 = –0.7k4. = 240 5.y ÷ (–0.3) = 146.7 –3.4 27 t 3.7 –3.5 888 – 44.01 3-6

More Related