Verified answer

7x - 3(x + 4) = 5x - 21

7x - 3x - 12 = 5x - 21

4x - 12 = 5x - 21

4x - 12 - 4x = 5x - 21 - 4x

- 12 = x - 21

- 12 + 21 = x - 21 + 21

9 = x

- - - - - - -s-

7x - 3(x + 4) = 5x - 21

7x - 3x - 12 = 5x - 21

4x - 12 = 5x - 21

-12 = 5x - 21 - 4x

-12 = x - 21

-12 + 21 = x

9 = x

----------

3x = 17 - 2(x + 1)

3x = 17 - 2x - 2

3x = 15 - 2x

3x + 2x = 15

5x = 15

x = 15/5

x = 3

With these two examples, you should be able to figure out the other two.

7x - 3(x + 4) = 5x - 21

7x - 3x -12 = 5x - 21

33 = x

3x = 17 - 2(x + 1)

3x = 17 - 2x -2

5x = 15

x=5

-3x - (-4x) = 21

-3x + 4x = 21

x=21

-4(2x + 8) = 32

-8x -32 = 32

-8x=64

x=-8

expand polynominal and combine like terms

7x-3x-12 = 5x - 21

7x-3x-5x = -21+12

-x = -9

x = 9

plugging 9 into original equation and checking for equality

7*9-3*(9+4) = 5*9 -21

63 - 3*13 = 45 - 21

63-39 = 24

24 = 24 QED

i was going to help you, but it seems that everyone has it going on. Good luck anyways. Once you get the hand of it you will fly righ through it.

7x-3x-12=5x-21

4x-12=5x-21

x=9

--------------------

3x=17-2x-2

3x=15-2x

5x=15

x=3

-----------------

-3x+4x=21

x=21

-------------------

-8x-32=32

-8x=64

x=-8