saseflower

Assuming you mean the seperate equations:

6y + 4 = 2(3y - 5)

Simplify

6y + 4 = 6y - 10

Subtract 6y from both sides

4 = -10

No solution

20f + (-8f - 15) = 2(4f - 5)

Simplify

20f -8f - 15 = 8f - 10

Simplify again

12f - 15 = 8f - 10

Subtract 8f from both sides

4f - 15 = -10

Add 15 to both sides

4f = 5

Divide by 4 on both sides

f = 4/5

3(1 + 2f) - 5 = 6f - 2

Simplify

3 + 6f - 5 = 6f - 2

Subtract 6f from both sides

3 - 5 = -2

Simplify

-2 = -2

Add 2 to both sides

0 = 0

Infinite Many Solutions

7x + 5 = 10(x - 7) - 3x

Simplify

7x + 5 = 10x - 70 - 3x

Simplify

7x + 5 = 7x - 70

Subtract 7x from both sides

5 = -70

No Solution

I'm not entirely sure this is correct, but I hope this helps :)

I personally am not very good at explaining things, so here are two websites that might help :)

Purplemath

http://www.purplemath.com/modules/strtlneq2.htm

Khan Academy

https://www.khanacademy.org/math/algebra/two-var-linear-equations-and-intro-to-functions/point-slope/v/idea-behind-point-slope-form

14/5 = 2.8

2x - 3y = 7

Plug in x

2(10) - 3y = 7

Simplify

20 - 3y = 7

Subtract 20 from both sides

-3y = -13

Divide -3 on both sides

y = 3/13

or

y = -4.3333333333333333

(I would do the fraction)

Hopefully this is what you were asking, I'm not entirely sure though :)

20/8 simplified would be 10/4 since the most you can simplify 20/8 by is 2 over 2

Thanks CPhill :)

-6w + 5 - 8 - 9d

Plug in w and d

-6(4) + 5 - 8 - 9(-4)

Simplify

-24 + 5 - 8 + 36

Simplify again

-19 - 8 + 36

And again

-27 + 36

And again

9

There's your answer :)

2/3 + 3/2

Find the common denominator by multiplying 2/3 by 2 over 2 and 3/2 by 3 over 3

4/6 + 9/6

Add

13/6

3(-3x - 1) - 9 = 5(x - 4)

Use the Distributive Property

-9x - 3 - 9 = 5x - 20

Simplify

-9x - 12 = 5x - 20

Add 9x to both sides

-12 = 14x - 20

Add 20 to both sides

8 = 14x

Divide by 14 on both sides

0.5714285714285714 = x

I would round

x = about 0.6

2570/30 = 85.6666666666666667

Next time use a calculator, it'll be faster than waiting for someone else to use one for you :)