## Search found 21 matches

Thu Oct 21, 2010 9:45 pm
Forum: Beginning Algebra
Topic: Writing equations for substitution and elimination.
Replies: 3
Views: 1818

### Re: Writing equations for substitution and elimination.

Okay. You have x=plan 1 and y=plan 2. You have plan 1 is 3*(plan 2). How did you get "plan 1 is 3*(plan 2) less 56"?

Use the variagles instead & plug them into "plan 1 is 3*(plan 2)" just like you did for "the sum of plan 1 and plan 2 is 56".
Wed Oct 20, 2010 8:28 pm
Forum: Beginning Algebra
Topic: Writing equations for substitution and elimination.
Replies: 3
Views: 1818

### Re: Writing equations for substitution and elimination.

I agree with (a) but how did you get (b)? What was your reasoning?
Mon Sep 06, 2010 4:43 pm
Topic: Radicals and Rational exponents: 5*cbrt[16] + cbrt[54]
Replies: 2
Views: 2532

### Re: Radicals and Rational exponents

Book Instructions: Add or subtract terms. 5\sqrt[3]{16}+\sqrt[3]{54} Hint: \sqrt[3]{16}\, =\, \sqrt[3]{8\times 2}\, =\, \sqrt[3]{2^3\, \times\, 2}\, =\, \sqrt[3]{2^3}\,\times\, \sqrt[3]{2} \sqrt[3]{54}\, =\, \sqrt[3]{27\times 3}\, =\, \sqrt[3]{3^3\, \times\, 2}\, =\,\sqrt[3]{3^3}\,\times\, \sqrt[3]...
Tue May 11, 2010 12:08 am
Forum: Calculus
Replies: 2
Views: 2445

You can use asymptotes from algebra: http://www.purplemath.com/modules/asymtote.htm

Since the degree of the numerator is more than the degree of the denominator, it has to 'go to infinity', so 'the limit does not exist'.

Hope that he,lps.
Thu Apr 01, 2010 11:18 pm
Topic: square root of (2x+20) + the square root of (2x)=10
Replies: 3
Views: 2529

### Re: square root of (2x+20) + the square root of (2x)=10

The square root of (2x+20) + the square root of (2x)=10 This is how I worked it: I squared both sides to get 2x+20+2x=10 How did you get this? Squaring the RHS gives 100, not 10. (10^2 does not equal 10) And what were your steps for the LHS? \left(\sqrt{2x+20}+\sqrt{2x}\right)^2 \left(\sqrt{2x+20}\...
Tue Mar 30, 2010 8:43 pm
Topic: help w/ logs, expos: log2 of 2x+log2 of x+5, 7^2x-4=14, etc
Replies: 1
Views: 1353

### Re: help w/ logs, expos: log2 of 2x+log2 of x+5, 7^2x-4=14,

log2 of 2x+log2 of x+5 what are the instructions for this? 7^2x-4=14 is the 4 in the power, or not? (for solving go here ) 3e^x+7=9 is the 7 in the power, or not? log3 of x+log3^(x-6)=3 log4 (5x-2)=3 they have a lesson here for solving log eqns Expanding confuses me too One of condensing too use th...
Tue Mar 09, 2010 6:37 pm
Forum: Intermediate Algebra
Topic: 20th digit to right of decimal point in 1.8987375 E-20
Replies: 1
Views: 1621

### Re: 20th digit to right of decimal point in 1.8987375 E-20

The "E-20" means that the number is in scientific notation. You can see how that works by going here . When the power on the 10 is negative, which was does the decimal point go? When the power is "-20", how many places does the point move? After you move the point that many places in that direction,...
Thu Feb 18, 2010 11:48 am
Forum: Arithmetic
Topic: How long does it take me to get to the town centre from the
Replies: 1
Views: 2312

### Re: How long does it take me to get to the town centre from the

How far away is the 120-km sign? How far away is the 60-km sign? So how far did you go at 120 kph? How long did this take? (Subtract to find the distance; then divide to get the fraction of an hour.) How far away is the 60-km sign? How far away is the 40-km sign? So how far did you go at 60 kph? How...
Mon Apr 13, 2009 9:58 pm
Topic: Two boats, each travelling at its own constant speed, start
Replies: 2
Views: 1738

### Re: Two boats, each travelling at its own constant speed, start

Thank you very much. That was very helpful.
Fri Apr 10, 2009 7:27 pm