Which pair of the following straight lines are parallel and how?

a. 2x + y + 1 = 0

b. y = 3x - 1

c. 2x - y = 3

d. y = 4x + 3

e. y = x/2 - 1

f. 6x - 2y = 0

g. 3y = x + 4

h. 2y = 5 - x

Step-by-step explanation:

assuming you know how to put the equations into y = m x + b already. All equations have to be put in that format to identify the slope. Parallel lines have the same slope.

a. y = - 2x - 1; slope - 2

b. y = 3x - 1; slope 3

c. y = 2x - 3; slope 2

d. y = 4x + 3; slope 4

e. y = x/2 - 1; slope 1/2

f. y = 3x; slope 3

g. y = x/3 + 4/3; slope 1/3

h. y = - x/2 + 5; slope - 1/2

There are only 2 that are alike. b and f both have a slope of 3. all the other slopes are different.

f and b

Step-by-step explanation:

if you put them in y-intercept form, both slopes are 3

In b. it's easy to see that 3x has a slope of 3.

In f. it's not so obvious. Just solve for y or use the shortcut m = - a/b where a is the coefficient of x and b is the coeff of y.

hence - (6/-2) = 3