If you mean: y = x+4 and y = 3x+8 then x = -2 and y = 2
The value of x is: x=7/8. Work: 5x-3=4-3x +3 +3 ________ 5x=7-3x +3x +3x ________ 8x=7 /8 /8 ________ x=7/8
2(3x + 4) = 6x + 8 3(x - 5) = 3x - 15 6x + 8 - 3x + 15 = 3x + 23
2(3x + 4) = 6x + 8 3(x - 5) = 3x - 15 6x + 8 - 3x + 15 = 3x + 23
If: 3x+8 = 14 Then: 3x = 14-8 So: 3x = 6 Divide both sides by 3: x = 2
3x² + 10x = 8 Rewrite as: 3x² + 10x - 8 = 0 The only way to get 3x² is 3x and x (3x + -- ) (x + --) The factors of 8 are {1 2 4 8} so the answers must be a pair of them. With 4 factors, and a negative sign (the -8), there are only 8 ways this can be written: (3x + 1)(x - 8) = 3x² - 23x - 8 (3x + 2)(x - 4) = 3x² -10x - 8 (almost) (3x + 4 )(x - 2) = 3x² - 8x - 8 (3x + 8)(x - 1) = 3x² +5x - 8 (3x - 1)(x + 8) = 3x² +23x - 8 (3x - 2)(x + 4) = 3x² + 10x -8 ◄ Success! (3x - 4)(x + 2) = 3x² +2x - 8 (3x - 8)(x + 1) = 3x² -5x - 8 Trial and error, error, error, is the key to this kind of problem. Seeing the -10x early can point you to see that maybe changing the signs can work. ■
3x + 8 = 8 Therefore, 3x = 0 x = 0/3 x = 0
3x + x + 8 = 204x + 8 = 204x = 12x = 3
3x - x = 3*8 - 8 = 24 - 8 = 16
3x = x+8 so 3x-x = 8 hence 2x = 8 and so x = 4
If x equals 8, then 3x equals 24. 24-x would equal 16.
3x + 8 = 20 3x = 20 - 8 3x = 12 3x = 12/3 x = 4
If you mean: y = x+4 and y = 3x+8 then x = -2 and y = 2
x-3x = -8 -2x = -8 x = 4
(3x - 9 =15) +9 = 3x=(24)/3 = x=8 x=8
The value of x is: x=7/8. Work: 5x-3=4-3x +3 +3 ________ 5x=7-3x +3x +3x ________ 8x=7 /8 /8 ________ x=7/8
3x-2=x+8 (+2) 3x=x+10 (-x) 2x=10 (/2) x=5