Enable contrast version

Tutor profile: Nancy W.

Inactive
Nancy W.
Math and Test Prep Tutor
Tutor Satisfaction Guarantee

Questions

Subject: SAT

TutorMe
Question:

The length of a rectangle is decreased by 25% and the width is doubled. How does the area of the rectangle change?

Inactive
Nancy W.
Answer:

The area of a rectangle is $$A = lw$$. Let's say the old rectangle has area $$A _{old} = l_{old} w_{old}$$ and the new triangle has area $$A_{new} = l_{new} w_{new}$$. The new length is 25% less than the old length: $$l_{new} = (1-0.25) l_{old} = 0.75 l_{old}$$ And the new width is doubled: $$ w_{new} = 2 w_{old}$$ Substituting, we find the area of the new triangle is $( A_{new} = l_{new} w_{new} = 0.75\cdot 2\cdot l_{old}w_{old}$)$( A_{new} = 1.5 A_{old}$) Thus we find that the new rectangle has an area 50% larger than that of the old rectangle.

Subject: Calculus

TutorMe
Question:

Find the derivative of the function $( \frac{\partial}{\partial x} (x^2 + 8x + 16)$).

Inactive
Nancy W.
Answer:

You may tackle each term separately, since the derivative operator acts linearly: $( \frac{\partial}{\partial x} x^2 + \frac{\partial}{\partial x} 8 x + \frac{\partial}{\partial x} 16$)$( 2x + 8 $)You may also simplify into:$(2(x + 4)$)

Subject: Algebra

TutorMe
Question:

Solve for x: $$x^2 + 8x + 16 = 0$$

Inactive
Nancy W.
Answer:

The simple solution is to recall the formula $(a^2 + 2ab + b^2 = (a+b)^2 $) where $$ a = x, b = 4$$. Thus, $(x^2 + 2\cdot x \cdot 4 + 4^2 = (x + 4)^2 = 0 $) $( x + 4 = 0$) So $$ x = -4$$. A more lengthy solution would be to use the quadratic formula: $(x = \frac{-b \pm \sqrt{b^2 - 4 ac}}{2a}$) where $$a = 1, b = 8, c =16$$. This yields: $(x = \frac{-8 \pm \sqrt{64 - 4 *16}}{2}$) $(x = \frac{-8 \pm \sqrt{0}}{2}$) $(x = -4$)

Contact tutor

Send a message explaining your
needs and Nancy will reply soon.
Contact Nancy

Request lesson

Ready now? Request a lesson.
Start Lesson

FAQs

What is a lesson?
A lesson is virtual lesson space on our platform where you and a tutor can communicate. You'll have the option to communicate using video/audio as well as text chat. You can also upload documents, edit papers in real time and use our cutting-edge virtual whiteboard.
How do I begin a lesson?
If the tutor is currently online, you can click the "Start Lesson" button above. If they are offline, you can always send them a message to schedule a lesson.
Who are TutorMe tutors?
Many of our tutors are current college students or recent graduates of top-tier universities like MIT, Harvard and USC. TutorMe has thousands of top-quality tutors available to work with you.
BEST IN CLASS SINCE 2015
TutorMe homepage
Made in California by Zovio
© 2013 - 2020 TutorMe, LLC
High Contrast Mode
On
Off