A line passing through (9, 15) and (2, y) is parallel to a line with slope 2. What is the value of y?
2007-11-23 08:37:17 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
(y - 15) / (2 - 9) = 2
y - 15 = - 14
y = 1
2007-11-23 09:06:27 · answer #1 · answered by Como 7 · 1⤊ 1⤋
You know the slope since it is parallel to a line with a slope of 2.
You have point #1's coordinates, being 9,15.
Just do "change in Y over change in X equals slope":
(y - 15) / (2 - 9) = 2
(y - 15) = 2 x (2 - 9)
y - 15 = 4 - 18
y - 15 = -14
y = -14 + 15
y = 1
2007-11-23 16:52:24 · answer #2 · answered by rich h 3 · 0⤊ 1⤋
gradient = y change / x change
2 = 15 - y / 9 - 2
plug in the numbers into the equation
2 = 15 - y / 7
14 = 15 - y
times both sides by 7
y = 15 -14
rearrange the equation
y = 1
voila get your answer
2007-11-23 16:49:39 · answer #3 · answered by Anonymous · 1⤊ 1⤋