Find the equation of a line through point (2, 5) and having a slope of 3/7.
Choices:
3x - 7y = -29
3x + 7y = 29
7x - 3y = 15
7x + 3y = 15
2006-10-11 12:57:07 · 6 answers · asked by Monique 1 in Science & Mathematics ➔ Mathematics
Start with y = mx + b
Here you know m = 3/7
y = (3/7)x + b
Now plug in x = 2 and y = 5
5 = (3/7)2 + b
Solve for b:
5 = 6/7 + b
b = 5 - 6/7
b = 35/7 - 6/7
b = 29/7
So the equation is:
y = (3/7)x + 29/7
Multiply through by y:
7y = 3x + 29
If you subtract 7y from both sides:
0 = 3x - 7y + 29
Now subtract 29 from both sides:
3x - 7y = -29
This looks just like answer a) 3x - 7y = 29
2006-10-11 13:00:44 · answer #1 · answered by Puzzling 7 · 0⤊ 1⤋
3x - 7y = -29
-7y=-3x-29
7y=3x+29
y=(3/7)x+29/7 slope is 3/7. Does it go through 2,5?
5=(3/7)*2+29/7
5=6/7+29/7=35/7=5 so YES THIS 1 IS RIGHT
3x + 7y = 29 slope=-3/7 so NO
7x - 3y = 15 slope=7/3 so NO
7x + 3y = 15 slope=-7/3 so NO
2006-10-15 12:34:32 · answer #2 · answered by yupchagee 7 · 0⤊ 0⤋
y-5=[3/7](x-2)
y-5=[3/7]x - [6/7]
y - [3/7]x - 5 +[ 6/7] = 0
y - [3/7]x - 29/7 =0 multiply both sides by -7
-7y + 3x + 29 =0
3x -7y = -29
2006-10-11 13:02:55 · answer #3 · answered by Anonymous · 0⤊ 0⤋
(y-5)= (3/7)(x-2)
3x - 7y = -29
2006-10-11 13:00:58 · answer #4 · answered by Sergio__ 7 · 0⤊ 0⤋
3x-7y=-29 100% sure
2006-10-11 13:06:40 · answer #5 · answered by 7 · 0⤊ 0⤋
the 2 is your x, the 5 your y. plug them in and see which "statement" is correct. so....for the third one option...
7(2) - 3(5) =15? is that right?
14 + 13 =15? nope. try one of the other ones ;)
2006-10-11 13:04:17 · answer #6 · answered by Anonymous · 0⤊ 0⤋