I am not very good with math and I have been trying to do this one and a few other problems for the last 3 hours. I am getting frustrated and need to learn how to do this type of problem. Thanks!
(x/3 + 3/4)(3x/4-3/5)
2007-02-23 10:16:59 · 5 answers · asked by mrsfinke2 1 in Education & Reference ➔ Homework Help
Like anything else, use FOIL to multiply it out
then you get
3x^2/12 - 3x/15 + 9x/16 - 9/20
The LCD is 240ths, multiply it out
60x^2/240 - 48X/240 + 135X/240 - 108/240, or
(60x^2 + 87x - 108)/240
This reduces to
[(5x -4)(12x + 27)]/240
2007-02-23 10:24:46 · answer #1 · answered by Anonymous · 0⤊ 0⤋
1. You need to mulitply out the brackets. i.e. multiply the 1st number in the 1st bracket by the 1st and second number in the second bracket (keep in mind the signs of these numbers)
2. After that, you find the LCM (least common multiple) of the denominators. So the lcm of 12, 15, 16 and 20 is 240 because all of them can go into 240 without leaving a remainder.
3. Group the x values and add, subt etc., whatever the sign is. Group the non x values and do the same. NB you cannot +,-,/ or * x values with non x values
1. 4x/12 - 3x/15 + 9x/16 - 9/20
2. 80x/240 - 48x/240 + 135x/240 - 180/240
3. 167x/240 - 180/240 .... final answer
2007-02-23 18:59:59 · answer #2 · answered by djvkj 1 · 0⤊ 0⤋
Do you know how to FOIL? That's what you do with this problem (at the beginning of the second polynomial separate {3x/4} to [3/4]x and the problem will be easier to solve.
2007-02-23 18:25:20 · answer #3 · answered by Adriana 4 · 0⤊ 0⤋
(x^2)/4 -x/5+9x/16-9/20
You could then go on to put the 2 x terms into one...
just do this type of a thing.. (A+B)(C+D) and then
AxB + AxD + BxC + BxD ... and include the minuses where necessary... and then cancel down within each term...
2007-02-23 18:30:23 · answer #4 · answered by David K 1 · 0⤊ 0⤋
ok it should be claerly after u do this
(x/3+3/4)(3x/4-3/5)
(x(1/3)+3/4))(3x(1/4)-3/5))
after that just look at +- and* :)
2007-02-23 18:38:23 · answer #5 · answered by Donatas B 1 · 0⤊ 0⤋