Question

下列方程用等式的性质如何解?

(1) X - 5 = 6 [X减五等于六]
(2) 0.3X = 45 [零点三X等于四十五]
(3) 2 - 1/4X =3 [二减四分之一X等于三]
(4) 5X + 4 = 0 [五X加四等于零]

Answer 1

(1) X - 5 = 6
两边同时加上5
X-5+5=6+5
X=11

(2) 0.3X = 45
两边同时除以0.3
0.3X÷0.3=45÷0.3
X=150

(3) 2 - 1/4X =3
两边同时减去0.3
2-1/4X-2=3-2
-1/4X=1
两边同时乘以-4
(-4)*(-1/4X)=1*(-4)
X=-4

(4) 5X + 4 = 0
两边同时减去4
5X+4-4=0-4
5X=-4
两边同时除以5
5X÷5=-4÷5
X=-4/5