Question

Identify the point (x1, y1) from the equation: y – 7 = 3(x + 2)
(Points : 1)
(–7, 2)
(7, –2)
(–2,7)
(2, –7)


Which equation is graphed here?
http://static.k12.com/eli/ecollege/589/7_31557/2_42817_8_31642/285bf9e57b26fe347558f6aff3c7b084ec543624/media/fd5fc8056c0c43341f322914dfa2e0f02040e8a1/mediaasset_1312640_1.jpg

A.)http://static.k12.com/eli/ecollege/589/7_31557/2_42817_8_31642/285bf9e57b26fe347558f6aff3c7b084ec543624/media/62e9b6751a88783d2f26455c7e21f5b61f704aab/mathml_0ae859efe41c8769c1c736ea599ada9e577d107c_1.gif
B.)http://static.k12.com/eli/ecollege/589/7_31557/2_42817_8_31642/285bf9e57b26fe347558f6aff3c7b084ec543624/media/85aaeb9b07ffdd83944f8ba01d47b689198839d7/mathml_0a9a8bbd3385d3cda975b845c6de85da9b36bfb2_1.gif
C.)http://static.k12.com/eli/ecollege/589/7_31557/2_42817_8_31642/285bf9e57b26fe347558f6aff3c7b084ec543624/media/575df0dfb028949aba00daa0efe3a2738185d444/mathml_88f415ff5eabe15ade36d2bc227174447fdb0698_1.gif
D.)http://static.k12.com/eli/ecollege/589/7_31557/2_42817_8_31642/285bf9e57b26fe347558f6aff3c7b084ec543624/media/c953a3b6dfaa0ecac8b747f0c5b5d8322328ebe5/mathml_c3f419e96032962326c70f8b59185e26372cf107_1.gif

Answer 1

your equation : y - 7 = 3(x + 2) is in point slope form....y - y1 = m(x - x1).....so x1 = 2 and y1 = -7.....(2,-7)
================
take 2 points on your line and and find the slope
(-2,4)...x1 = -2 and y1 = 4
(4,-5)...x2 = 4 and y2 = -5
now sub into slope formula : (y2 - y1) / (x2 - x1)
slope(m) = (-5 - 4) / (4 - (-2)
slope(m) = -9/6 -- reduce
slope(m) = -3/2

now use point slope form : y - y1 = m(x - x1)
slope(m) = -3/2
use either of your points..
(4,-5)...x1 = 4 and y1 = 5
now we sub
y - (-5) = -3/2(x - 4)
y + 5 = -3/2(x - 4) <==answer A