Monday

July 28, 2014

July 28, 2014

Posted by **Rachel** on Friday, January 28, 2011 at 4:09pm.

ii) If the line 7x+ky=7 is parallel to 4x-6y=-5, then what is the value of k? Answer: k = ?

- Math -
**Reiny**, Friday, January 28, 2011 at 4:37pmThe two equations are easy to solve, just add up the two equations and the y term will drop out to get

11x = 2

x = 2/11

sub back into the second (or the first) to get

7(2/11) + 6y = 7

times 11

14 + 66y = 77

66y = 63

y = 63/66 = 21/22

slope of first line = -7/k

slope of 2nd line = 4/6 = 2/3

so -7/k = 2/3

cross-multiply

2k = -21

k = -21/2

**Related Questions**

geometry - Martin drew a pair of perpendicular lines and a pair of parallel ...

math - In the xy-plane, lines a and b intersect at point (5,-2), and lines b and...

math 214 - A student claims that if any two planes that do not intersect are ...

Algebra - If you have these three origins: (0,0) (0,952) (863,0) How do you find...

math - In the xy-plane, line l passes through the origin and is perpendicular ...

math graphs - 4. Which equation would you use to find out if the two lines in ...

Algebra 1 - 1.To solve the linear system below, which substitution of unkowns is...

Math - Perry draws two planes, K and L, as shown. Which statement is true? ...

Geometry - Prove that the tangents to a circle at the endpoints of a diameter ...

Algebra 1 - 1. Which line is the flattest (or is less steep)? Why? y = 5x -6 y...