Question

which equation describes a line that is NOT parallel to the lines described by the other three equations?
1. 2x+7y=8
2. -6x-21y=-5
3.-10.5y=3x
4.y+8=(2/7)(x-7)

Answer 1

OH MY GAWD

Answer 2

the struggle!

Answer 3

Can you check the third equation?

Answer 4

Yup thats the exact one on my test. its -10.5y=3x

Answer 5

Ok.
Solve each equation for y and write it in the form y = mx + b.
m, the number that multiplies x, is the slope.

Answer 6

Let's try the first one:

\(2x+7y=8\)

Subtract 2x from both sides:

\(7y = -2x + 8\)

Divide both sides by 7:

\(y = -\dfrac{2}{7} x + \dfrac{8}{7} \)

The slope is \(-\dfrac{2}{7} \)

Now do the same to all other equations and compare their slopes.

Answer 7

By "do the same to all other equations" I mean solve all other equations for y and put them in the y = mx + b form.

Answer 8

ok so 2x+7y=8 is y=-2x/7+8/7
-6x-21y=-5 is y=-2x/7+5/21
-10.5y=3x is y=-0.28571429x
and y+8=2/7(x-7) is y=2x/7-10

Answer 9

1. slope is -2/7
2. slope is -2/7
3. slope is -0.28571429
4. slope is 2/7

Answer 10

so is it 3? @mathstudent55

Answer 11

\(-6x-21y=-5\)

\(-21y = 6x - 5\)

\(y = -\dfrac{6}{21}x + \dfrac{5}{21} \)

\(y = -\dfrac{2}{7}x + \dfrac{5}{21} \)

Correct.

Answer 12

Thankyou so much for your help!

Answer 13

\(-10.5y=3x\)

\(y = - \dfrac{3}{10.5} x \)

\(y = - \dfrac{6}{21} x \)

\(y = - \dfrac{2}{7} x \)

Incorrect.

Answer 14

You should keep the third one as a fraction. The you will see that the third one is also -2/7.
The answer is D, 2/7

Answer 15

1. slope is -2/7
2. slope is -2/7
3. slope is -0.28571429 = -2/7
4. slope is 2/7

The only different slope is D.