SOLUTION: Find the value of x or y so that the line through the points has the given slope (5,7) and (9,y); slope -5/2

Algebra ->  Graphs -> SOLUTION: Find the value of x or y so that the line through the points has the given slope (5,7) and (9,y); slope -5/2      Log On


   

Question 1091270: Find the value of x or y so that the line through the points has the given slope
(5,7) and (9,y); slope -5/2
Found 2 solutions by MathLover1, MathTherapy:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
given:
(5,7) and (9,y); slope -5%2F2
use slope-point formula
y-y%5B1%5D=m%28x-x%5B1%5D%29 ...since given m=-5%2F2 and (5,7) we can find equation of a line
y-7=-%285%2F2%29%28x-5%29
y-7=-%285%2F2%29x-%285%2F2%29%28-5%29
y-7=-%285%2F2%29x%2B25%2F2
y=-%285%2F2%29x%2B25%2F2%2B7
y=-%285%2F2%29x%2B25%2F2%2B14%2F2
y=-%285%2F2%29x%2B39%2F2
now find y for (9,y)
y=-%285%2F2%299%2B39%2F2
y=-45%2F2%2B39%2F2
y=-6%2F2
y=-3
so, your point is (9,-3)




Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
Find the value of x or y so that the line through the points has the given slope
(5,7) and (9,y); slope -5/2
All you have to do is use the slope formula: 

%287+-+y%29%2F%285+-+9%29+=+-+5%2F2 ----- Substituting     

%287+-+y%29%2F%28-+4%29+=+-+5%2F2

2(7 - y) = 20 ------ Cross-multiplying

2(7 - y) = 2(10)

7 - y = 10



That's all! It's as simple as that!