3x + 4y = --5
x --3y = --11
i got some ugly numbers for my answers so i am thinking i did somethings wrong, my answers are x= --227/13 and y= 28/13
2007-11-29 17:27:54 · 5 answers · asked by Boo Radley 4 in Science & Mathematics ➔ Mathematics
answers won't always be pretty in mathematics. Get used to it the higher you get.
anyway,
y is good. Your x is off. Plug that y into the 2nd equation and you should get -59/13. Check your signs
2007-11-29 17:54:02 · answer #1 · answered by Gills 1 · 1⤊ 0⤋
Values of y:
3x + 4y = - 5
4y = - 3x - 5
y = (- 3x - 5)/4
x - 3y = - 11
3y = x + 11
y = (x + 11)/3
Value of x:
(- 3x - 5)/4 = (x + 11)/3
3(- 3x - 5) = 4(x + 11)
- 9x - 15 = 4x + 44
13x = - 59
x = - 59/13
Value of y:
= (- 3[- 59/13] - 5)/4
= (177/13 - 65/13)/4
= (112/13)/4
= 28/13
Answer: x = - 59/13, y = 28/13
Proof:
- 59/13 - 3(28/13) = - 11
- 59/13 - 84/13 = - 11
- 143/13 = - 11
- 11 = - 11
2007-11-30 02:57:33 · answer #2 · answered by Jun Agruda 7 · 3⤊ 0⤋
x = 3y - 11
9y - 33 + 4y = - 5
13 y = 28
y = 28 / 13
x - 84/13 = - 11
x = 84/13 - 143/13
x = - 59 / 13
x = - 59/13 , y = 28/13
2007-11-30 10:41:12 · answer #3 · answered by Como 7 · 1⤊ 1⤋
Gills answer (-59/13, 28/13) seems to satisfy both equations.
2007-11-30 01:59:03 · answer #4 · answered by answerING 6 · 1⤊ 0⤋
x=(-5-4y)/3 --- eqn.1, now put this eqn to x-3y=-11.. u ll get da value of 'y', then put the value of y in : 3x+4y=-5, u ll get da x value
2007-11-30 13:41:47 · answer #5 · answered by emran m 1 · 0⤊ 0⤋