Step-by-step explanation:
For finding k we'll have to plug in the x-value of the coordinate (3,k) into the equation, and solve for the y:
5(3) - 2y = 7
15 - 2y = 7
2y = 8
y = 4 => k =4
2) I assume the gradient is the slope of the line. If so, just isolate the y in the original equation and see what's the coefficient of the x:
-2y = -5x + 7
y = (5/2)x + 7/2 => the gradient is 5/2
3) the condition of perpendicularity is expressed by the following relation:
a * a' = -1
Where a is the slope of the first line and a' of the second line. We need to find a' that will be:
-1/a = -1/(5/2) = -2/5
The perpendicular line will be:
y = (-2/5)x + b
We need to find b, and we know that this line passes through A (1,-1):
-1 = (-2/5)*1 + b
b = -1+(2/5) = -3/5
The equation will be:
y = (-2/5)x - 3/5.
4) I don't know what that symbol means (pV2).
