Question

The coordinates below represent two linear equations.

How many solutions does this system of equations have?
Line 1
x y
–1 6
0 4
Line 2
x y
0 7
1 5
A.0
B.exactly 1
C.exactly 2
D.infinitely many
please help. will fan and medal :)

Answer 1

line 1...slope = (y2 - y1) / (x2 - x1)
slope = (4 - 6) / (0 - (-1)
slope = -2/1
slope = -2

y = mx + b
6 = -2(-1) + b
6 = 2 + b
4 = b

equation is : y = -2x + 4
------------------
line 2
slope = (5 - 7) / (1 - 0)
slope = -2/1
slope = -2

y = mx + b
7 = -2(0) + b
7 = b

equation is : y = -2x + 7
-------------------
if they have same slope but different y intercepts, then the lines are parallel and do not cross. Therefore, they have 0 solutions

Answer 2

ohh. i see now. thanks :)

Answer 3

YW :)