http://www.e-xamit.ie/2005test/php/GetDocByID.php?id=13360&prep=13363&soln=13360&tip=13368&port=13365
i dont see how the second line workes, mainly the last bit (how they got 5over2 +1+5
cheers!
2007-11-27 06:50:37 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
This is simple substitution and simple Algebra. When substituting x=(5/2) and y=(1/3) into the numerator (the top quantity of the fraction), you get (5/2)+3(1/3)+5. Just solving the numerator you get (5/2)+1+5.
The main difference is 3(1/3). You can multiply it and get 3/3 which equals one, or take it into fractions (3/1)(1/3). Multiply corresponding numerators and denominators and you will get 3/3 which equals one.
2007-11-27 07:04:05 · answer #1 · answered by Bartman 1 · 1⤊ 0⤋
They basically plugged in x and y
5/2=x
1/3=y
so the top line which is x+3y+5
ends up being (5/2)+3(1/3)+5 (when you substitute x and y)
so you apply multiply the 3(1/3) which equals 1 and end up with the 5/2+1+5
Then do the same thing for the bottom
2007-11-27 07:06:34 · answer #2 · answered by ~soy-yo~ 3 · 0⤊ 0⤋
[ x + 3y + 5] / [5x + 2y]
Given that x= 5/2 and y = 1/3
Where ever 'x' and 'y' are seen in the equation , substitute in 5/2 and 1/3.
Hence.
[5/2 +3(1/3) + 5] / [ 2(5/2) + 2(1/3)]
It is the convention amongst mathematicians that when a statement is written 3(1/3) it means 3 x 1/3, and 3 x 1/3 = 1.
Similarly 2(5/2) = 2 x 5/2 = 5, hence
[5/2 + 1 + 5] / [5 + 2/3]
17/2 / 17/3 =
17/2 x 3/17 = 2/3 : the '17's' cancel out.
2007-11-27 08:04:02 · answer #3 · answered by lenpol7 7 · 0⤊ 0⤋
x+3y+5 x=5/2 y=1/3
5/2+3*(1/3)+5
5/2+(3/3)+5
5/2+1+5
3*(1/3)=(3*1)/3=3/3=1
2007-11-27 07:18:42 · answer #4 · answered by emokirchev 2 · 0⤊ 0⤋
what does x equal? That's all they did was put what x equals in the place of x.
2007-11-27 06:59:19 · answer #5 · answered by healthspot_2000 4 · 0⤊ 0⤋
tut
was just about to explain it to you
but
bartman beat me to it
lol
2007-11-27 14:18:04 · answer #6 · answered by pepzi_bandit 2 6 · 1⤊ 0⤋