## Janet Yang

U.S.
Available
##### Expertise

I can answer questions in Algebra, Basic Math, Calculus, Differential Equations, Geometry, Number Theory, and Word Problems. I would not feel comfortable answering questions in Probability and Statistics or Topology because I have not studied these in depth.

##### Experience in the area

I tutor students (fifth through twelfth grades) and am a Top Contributor on Yahoo!Answers with over 24,000 math solutions.

##### Publications

Co-author of An Outline of Scientific Writing: For Researchers With English as a Foreign Language

##### Education/Credentials

I have a Bachelor's degree in Applied Mathematics from the University of California at Berkeley.

##### Past/Present Clients

George White Elementary School. Homework Help program at the Ridgewood Public Library, Ridgewood, NJ. Individual students.

### Recent Reviews from Users

K = Knowledgeability    C = Clarity of Response    P = Politeness

### Recent Answers from Janet Yang

#### 2017-04-20 Acres Per Hour Follow-up:

"equipment is moving at 4.5 mph"  (4.5 miles)/h × (5280 ft)/mile = (23,760 ft)/h  The equipment travels 23,760 feet per hour.    "equipment is 9 ft wide"  coverage = (9 ft) × (23,760 ft)/h   = (213,840

#### 2017-03-10 Ratio:

I disagree that ratios must use the same units. A common example is the ratio of boys to girls in a classroom, which clearly uses different units.    While you can say "8 mm to 5 ft," it is better to use

#### 2016-11-29 Width Follpw-up:

area of metal = y²  area of wood = x²-y²  y²:(x²-y²) = 25:39  39y² = 25(x²-y²) = 25x² - 25y²  64y² = 25x²  y² = (25/64)x²  y = √((25/64)x²) = (√25/√64)√x² = (5/8)x    w = (x - y)/2

#### 2016-07-26 Amount Invested:

B = mA  C = A+B    By substitution, C = A + mA.  By the distributive rule, A + mA = A(1+m).  :::::  D = C+B  By substitution, D = A(m+1) + mA.  By the distributive rule, D = A(2m+1).    It is given that

#### 2016-07-26 Amount Invested:

"A, B, C, and D invest \$s."  A+B+C+D = s    "B invests m times as much as A"  B = mA    "C invests as much as A and B combined"  C = A+B = A+(mA) = A(m+1)    "D invests as much as C and B combined"  D