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  • Brainly User
2015-11-19T16:34:49+08:00

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1) 3x - 2 = 7
    3x = 7 + 2
    3x = 9
    3x/3 = 9/3
    x = 3

2)  2a + 15 = 5
     2a = 5 - 15
     2a = -10
     2a/2 = -10/2
     a = - 5

3)  5 + 4b = - 11
    4b = - 11 - 5
    4b = - 16
    4b/4 = - 16/4
    b = - 4

4)  x + 8 = 63
    x = 63 - 8
    x = 55

5)  4d - 5 = 2d + 7
    4d - 2d = 7 + 5
    2d = 12
    2d/2 = 12/2
    d = 6

6)  9c + 3 = 8c + 5
     9c - 8c = 5 - 3
     c = 2

7)  5(2x - 1) + 6 = 7x - 8
     10x - 5 + 6 = 7x - 8
     10x + 1 = 7x - 8
     10x - 7x = -8 -1
      3x = -9
      3x/3 = -9/3
      x = -3

8) 4y + 5 = 2y + 73
    4y- 2y = 73 - 5
     2y = 72
     y = 36

9)  4x = 2x + 8
    4x - 2x = 8
    2x = 8
    2x/2 = 8/2
    x = 4  

10)  10m - 10 = 10
       10m = 10 + 10
       10m = 20
        10m/10 = 20/10
        m = 2


(Note
:  I hope you posted items 4 and 8 correctly :-) 

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2015-11-19T19:06:44+08:00
I'll just tell you HOW to solve, but I won't solve EVERYTHING.
1.) 3x-2=7

3x=7+2 (Transpose 2 to isolate the variables from the real nos. Its sign will be its 
             opposite value)

3x=9 (Simplify)

3x = 9
3      3 (Divide both sides with the numerical of the varaiable)

x = 3 (Simplify and Viola!)


2.) 2a + 15 = 5

2a = 5 -15 (Transpose)

2a = -10 (Simplify)

2a = -10
2        2  (Divide by coefficient)

a = -5


If you want to check if your answer is correct, substitute your answer to the variable in the original equation.
1. 3x-2=7
x = 3
So, 3(3)-2=7
9-2=7
7=7

2. 2a+15=5
a=-5
So, 2(-5)+15=5
-10+15=5
5=5

Try answering the rest! :)

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