Which pair of equations below represent parallel lines? and y = 9 and x = 18 y = 4x + 9 and y = 4x – 9 y = 5x + 15 and y = –5x + 15

The correct option is 2.

Step-by-step explanation:

The slope of two parallel lines are equal.

The slope intercept form of a line is

Where, m is slope and b is y-intercept.

In option 1, the equation of lines are

The first line is a horizontal line and the second line is a vertical line. Therefore they are not parallel line. Option 1 is incorrect.

In option 2, the equation of lines are

By using the slope intercept form of a line, the slope of first line is 4 and the slope of second line is 4.

Since the slope of both lines are same, therefore both lines are parallel. Option 2 is correct.

In option 2, the equation of lines are

By using the slope intercept form of a line, the slope of first line is 5 and the slope of second line is -5.

Since the slope of both lines are not same, therefore both lines are not parallel. Option 3 is incorrect.

Option B.

Step-by-step explanation:

If two lines are in the form of y = mx + c and y' = m'x' + c'

and the given lines are parallel then their slopes will be same.

For this condition m = m'

Now we will analyse each option for the condition that the given lines are parallel lines.

Option A. y = 9 and x = 18

These lines are horizontal and vertical lines so they are not parallel.

Option B. y = 4x + 9 and y = 4x - 9

y = 4x + 9 slope of the line is m = 4

y = 4x - 9 slope of this line is m' = 4

Slopes are same so both the lines are parallel.

Option C. y = 5x + 15 and y = -5x + 15

for y = 5x + 15 slope m = 5

for y = -5x + 15 slope m' = -5

Slopes are not equal so the lines are not parallel.

Option B. is the answer.

answer: 91

step-by-step explanation:

26 is 33.33% of 78

step-by-step explanation:

26 is what percent of 78?

26 is p% of 78

equation: y = p% * x

solving our equation for p

p% = y/x

p% = 26/78

p = 0.3333

convert decimal to percent:

p% = 0.3333 * 100 = 33.33%