Answer:
y = 4x
y = -1/3 × x + 6
y = x + 1
y = 1
y = 5x
Explanation:
the slope of a line is the factor of x in the equation representing the ratio of y/x. it stands for the number of units y changes, when x changes by another number of units.
like the factor 4 tells us that when x changes by 1, then y changes by 4.
a line parallel to another line means their slopes are identical (otherwise they could not be parallel).
the slope of a perpendicular line (cutting the other line in a 90 degree angle) is simply reversing y and x in the slope ratio. so, a slope of 4 (4/1) would simply turn into 1/4.
now the 5 tasks are easy, right ?
A y=4x-1, B y=4x + c
and because B passes through the origin = (0,0),
c is 0 (0=4×0 + c = c)
B y = 4x
A y=-3x+1, B y=-1/3 × x + c
and B passes through (12,2), 2 = -1/3 × 12 + c = -4 + c,
c = 2 + 4 = 6
B y = -1/3 × x + 6
A y = ax + c for (5,6) and (7,8), B is identical
6 = a×5 + c => c = 6 - a×5
8 = a×7 + c => 8 = a×7 + 6 - a×5 = a×2 + 6
=> a×2 = 8-6 = 2
=> a = 1, c = 6 - 1×5 = 1
=> A and B y = x + 1
A is vertical. B is perpendicular to it. perpendicular to vertical is horizontal. so, B is a flat line. which means y is a constant value (the same value for whatever value of x you want to use). so it goes flat in parallel to the x-axis through what value of y ? the point (4,1) tells us that y=1
and that is the equation for B
A 15x -3y = -6 => 3y = 15x + 6 => y = 5x + 2
B is parallel, so y = 5x + c
and B passes through (4,20), 20 = 5 × 4 + c = 20 + c,
c = 20 - 20 = 0
B y = 5x