Friday

December 19, 2014

December 19, 2014

Posted by **sharon** on Friday, July 11, 2014 at 8:19pm.

without graphing, tell whether the graphs of each pair of equations are perpendicular.

- Alegbra -
**Barry**, Friday, July 11, 2014 at 8:33pmDear sharon,

the first equation

y = -7x - 9

slope= -7

y-intercept= -9

the second equation

-3y = 21x + 7

y = -7x -(7/3)

slope= -7

y-intercept= -(7/3)

To determine whether the two lines are perpendicular

slope of equation 1 X slope of equation 2 must be -1.

But in this case,

slope of equation 1 X slope of equation 2 = 49 instead of -1

so the two lines are not perpendicular.

(However, slope of equation 1 = slope of equation 2 and the y-intercept of the two equations are not the same, so we know that the two lines are parallel to each other.)

Hope it helps!

Wishing you the best of luck,

Barry

- Alegbra -
**Steve**, Friday, July 11, 2014 at 8:34pmthe slopes are the same, so they are either parallel or the same line.

If you multiply the 1st by -3, the constant term is different from 7, so the lines are parallel.

**Answer this Question**

**Related Questions**

Alegbra - I really don't understand what I am doing. Needing help! With ...

Alegbra - Will be the graphs of each of these equations be perpendicular. 1.y=7x...

Math - 38. Tell whether the lines for the pair of equations are parallel, ...

math help please - Tell whether the lines for each pair of equations are ...

Math Help?! 7th grade. - 1. Determine which ordered pair is a solution of y = x...

graphing - Determine whether the graphs of the two lines are parallel. y+3=3x 6x...

math help please - Tell whether the lines for each pair of equations are ...

math help please - Tell whether the lines for each pair of equations are ...

math help please - Tell whether the lines for each pair of equations are ...

math help please - Tell whether the lines for each pair of equations are ...