Woah! This might take a long time but let us answer this by simplifying it first using the combination of terms. We should use the PMDAS and the left-to-right method if it is already pure Subtraction and Addition or pure Multiplication and Division.
Okay, number 1:
1.) 3x + 4 - 8 / 2 x 5 - 3 + 1 = 3
3x + 4 - [(8/2) x 5] - 3 + 1 = 3
3x + 4 - [ (4) x 5 ] - 3 + 1 = 3
3x + 4 - 20 - 3 + 1 = 3
3x -16 - 3 + 1 = 3
3x - 19 + 1 = 3
3x -18 = 3
3x = 3 + 18
3x = 21
x = 7
Check:
3x + 4 - [ (8/2) x 5 ] - 3 + 1 = 3
3(7) + 4 - [(8/2) x 5] - 3 + 1 = 3
21 + 4 - [ 4 x 5 ] - 3 + 1 = 3
21 + 4 - 20 - 3 + 1 = 3
25 - 20 -3 + 1 = 3
5 - 3 + 1 = 3
2 + 1 = 3
3 = 3, CORRECT!!!
Number 2.
2.) 2x + 6 - 12 x 3 / 2 + 3x - 20 + 5 = 6
2x + 6 - [(12 x 3) / 2] + 3x - 20 + 5 = 6
2x + 6 - [ 36 / 2 ] + 3x - 20 + 5 = 6
2x + 6 - 18 + 3x - 20 + 5 = 6
2x - 12 + 3x - 20 + 5 = 6
5x - 12 - 20 + 5 = 6
5x - 32 + 5 = 6
5x - 27 = 6
5x = 6 + 27
5x = 33
x = 33/ 5
Check:
2x + 6 - [(12 x 3) / 2] + 3x - 20 + 5 = 6
2x + 6 - [ 36 / 2 ] + 3x - 20 + 5 = 6
2x + 6 - 18 + 3x - 20 + 5 = 6
2(33/5) + 6 - 18 + 3(33/5) - 20 + 5 = 6
66 / 5 - 12 + 99/5 - 20 + 5 = 6
165 / 5 - 32 + 5 = 6
165 / 5 - 27 = 6
165 / 5 = 6 + 27
165 / 5 = 33
33 = 33, CORRECT!!!
So the answers are:
1.) 7
2.) 33/5
(Note: You can be sure that these are correct if my answers are not wrong. Please correct me if I have a mistake, :) : ) :) )
