146k views
0 votes
Which two lines are parallel?

I. 5y = 4x - 5

II. 7y = 3 - 5x

III. 7y + 5x = -1

a) I and II
b) I and III
c) II and III
d) None are parallel

1 Answer

4 votes

Final answer:

Equations II and III both have the same slope of -5/7, which means these two lines are parallel. Hence, the two parallel lines are II and III, making the correct answer (c) II and III.

Step-by-step explanation:

To determine which two lines are parallel, we need to consider the slopes of each line. In slope-intercept form, y = mx + b, the coefficient m represents the slope. We can convert the given equations into slope-intercept form to identify their slopes.

  • For equation I, 5y = 4x - 5, we divide by 5 to get y = (4/5)x - 1. The slope here is 4/5.
  • For equation II, 7y = 3 - 5x, we can rearrange it to 7y = -5x + 3 and then divide by 7 to yield y = -(5/7)x + 3/7. The slope for this line is -5/7.
  • For equation III, 7y + 5x = -1, we rearrange to get 7y = -5x - 1 and then divide by 7, resulting in y = -(5/7)x - 1/7. The slope is again -5/7.

Lines with the same slopes are parallel. Therefore, equation II and III have the same slope of -5/7 and are parallel to each other. The correct answer is c) II and III.

User Tmgirvin
by
8.8k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories