Answer:
A linear equation can be written as:
y = a*x + b
Where a is the slope and b is the y-intercept.
If we want to have a slope equal to -2, then our line will be something like:
y = -2*x + b
Now, we also want this line to pass through the point (3, -4)
This means that when x = 3, we must have y = -4
Then:
-4 = -2*(3) + b
-4 = -6 + b
-4 + 6 = b
2 = b
Then our line is:
y = -2*x + 2
Now, the second part says that:
If this line contains the points (2,8) and (5.b), find a and b.
This is incorrectly written because this line clearly does not contain the point (2, 8), so i guess the actual problem is something like:
If this line contains the points (a,8) and (5.b), find a and b.
If the line contains the point (a, 8), this means that when y = 8, we must have x = a.
Then:
8 = -2*a + 2
8 - 2 = -2*a
6 = -2*a
6/-2 = -3 = a
a = -3
Similar reasoing for the other point, if the line contains the point (5, b), this means that when x = 5, we have y = b.
Then:
b = -2*5 + 2 = -10 + 2
b = -8