David B asked in Science & MathematicsMathematics · 1 decade ago

# Tell weather the graphs pf the pair of equations are parallel, perpendicular or neither.?

Tell weather the graphs pf the pair of equations are parallel, perpendicular or neither.

6x + 6y = 3

6x - 6y = 5

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• Anonymous

the pair of eqations a1x+b1y =c1

and a2x + b2y = c2 are

(1.) parallel if a1/ b1 = a2/b2 (derived from equal slopes concept).

(2.) perpendicular if a1a2+b1b2 =0.

the above equation has a1 = 6, b1 =6, a2 = 6., b2 = - 6

clearly, a1a2 + b1b2 =36 -36 =0.

hence,the graphs of the pair of equations are perpendicular.

• 1 decade ago

First, put the equations is Y = mX + b form:

9X + 3Y = 14

3Y = 14 - 9X

3Y = -9X + 14

Y = -3X + 14/3

Now you know the SLOPE: -3

when you put the second equation into LINE for (Y=mX+b)

compare the two slopes:(M with M)

if they are the SAME, the lines are parallel (unless the equations are identical, in which case there is only one line)

IF the two SLOPES (Ms) are NEGATIVE INVERSES of each other, they are perpendicular. Examples

-3 is perp. to 1/3

-1/4 is per to 4

by the way, if slope = 0, it's parallel to X axis: Y = 3 is an example

then the perpendicular is the Y axis or X = n, e,.g. X=4.5 or X=-12

• cidyah
Lv 7

6x + 6y = 3

6y=-6x+3

y= -x+3/6

y=-x+1/2 ----(1)

6x - 6y = 5

-6y=-6x+5

y=x -5/6 ---(2)

The slope of equation (1) is -1

The slope of equation (2) is 1

The product of the slopes is -1

They are perpendicular.