Bonjour,
a)
2x= 10 -4
2x= 6
x= 6/2 = 3
b)
3x+2x =10 +5
5x = 15
x= 15/5 = 3
c)
2x+4 -x+8 = 10x +x+3
x +12 = 11x +3
12-3 = 11x -x
9 = 10x
x= 9/10
d)
2x+8 = -18 +6x
+8+18 = 6x -2x
26 = 4x
x= 26/4 = 13/2
e)
2x² -3x +8x -12 = 10 + 2x²
2x² +5x -12 =10+2x²
2x² -2x² +5x = 10+12
5x = 22
x= 22/5
f)
x² -5x +5x -25 = 50
x² -25 = 50
x² = 50 +25
x² = 75
x= √75
g)
4x² +20x -x -5 = 19x
4x² +19x -5 = 19x
4x² +19x -19x =5
4x² = 5
x² = 5/4
x= √5/4
