For more information, please see full course syllabus of Pre Algebra

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For more information, please see full course syllabus of Pre Algebra

For more information, please see full course syllabus of Pre Algebra

### Solving Equations by Multiplying

- You can use the Multiplication Property of Equality to isolate the variable by multiplying both sides of the equation by the reciprocal of the fraction next to the variable.
- Two numbers are reciprocals if their product is 1. The reciprocal is also known as the multiplicative inverse.
- Multiplying by the reciprocal is the same as dividing by the same fraction.

### Solving Equations by Multiplying

6x = 2[18/5]. Solve for x.

- x = 2[18/5] ×[1/6]
- x = [28/5] ×[1/6]
- x = [14/5] ×[1/3]

x = [14/15]

[3/7]x = 10. Solve for x.

- x = 10 ×[7/3]
- x = [70/3]

x = 23[1/3]

[9/10]x = − [7/12]. Solve for x.

- x = − [7/12] ×[10/9]
- x = − [7/6] ×[5/9]

x = − [35/54]

5x = − [7/10]. Solve for x.

- x = − [7/10] ×[1/5]

x = − [7/50]

− [5/11]x = [19/20]. Solve for x.

- x = [19/20] ×− [11/5]
- x = − [209/100]

x = − 2[9/100]

− [9/8]x = 1.3. Solve for x.

- − [9/8]x = 1[3/10]
- x = 1[3/10] ×− [8/9]
- x = [13/10] ×− [8/9]
- x = − [104/90]

x = − 1[14/90]

6.2 = − 10x

- 6[2/10] = − 10x
- 6[1/5] = − 10x
- [31/5] ×− [1/10] = x

x = − [31/50]

Jessica has 1[2/3] more money than Duy has. Duy has $ 20.50. How much money does Jessica have?

- $ 20.50 ×1[2/3] =
- 20[1/2] ×1[2/3] =
- [41/2] ×[5/3] =
- [205/6] =

$ 34.17

Lionel has 7[4/5] more yarn than Michelle has. Michelle has 2[1/3] feet of yarn. How much yarn does Lionel have?

- 2[1/3] ×7[4/5] =
- [7/3] ×[39/5] =
- [7/1] ×[13/5] =
- [91/5] =

18[1/5] feet

Lauren was refilling her pool after a hot day. The level of water rose 15[3/4] inches in 9[1/2] minutes. How many inches per minute did the water level rise?

- 15[3/4] ÷9[1/2] =
- [63/4] ÷[19/2] =
- [63/4] ×[2/19] =
- [63/2] ×[1/19] =
- [63/38] =

1[25/38] inches per minute

*These practice questions are only helpful when you work on them offline on a piece of paper and then use the solution steps function to check your answer.

Answer

### Solving Equations by Multiplying

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

- Intro 0:00
- What You'll Learn and Why 0:06
- Topics Overview
- Vocabulary 0:20
- Multiplicative Inverse
- Solve Each Equation 0:51
- Example 1: Solve the Equation
- Example 2: Solve the Equation
- Writing Multiplication Equations 3:30
- Example: Water Level
- Extra Example 1: Solve the Equation 5:15
- Extra Example 2: Solve the Equation 6:28
- Extra Example 3:Money 7:26
- Extra Example 4: Solve the Equation 9:45

0 answers

Post by sherman boey on August 7, 2014

for the example 1 42 can be divided by 7 why do u need to times them to a bigger number?