X÷= X＋X= 4X－6×=2

÷X= X = X = ×

X÷ =× 4x－3 ×9 = 29 x + x = 4

X－21×=4

6X＋5 =13.4 X-X= 4χ－6＝38

5X= X= X÷=

X÷=12 X= X=×

X÷=÷ X-0.25= =30%

4+0.7X=102 X+X=42 X+X=105

X-X=400 X-0.125X=8 =