28×3+4.5x=93 2.6x+1.8=7 3x-0.86=3.61 x+16=1.4×15 4x-2×3=102
1个回答

(1)28×3+4.5x=93

84+4.5x=93

84+4.5x-84=93-84

4.5x÷4.5=9÷4.5

x=2;

(2)2.6x+1.8=7

2.6x+1.8-1.8=7-1.8

2.6x÷2.6=5.2÷2.6

x=2;

(3)3x-0.86=3.61

3x-0.86+0.86=3.61+0.86

3x÷3=4.47÷3

x=1.49;

(4)x+16=1.4×15

x+16=21

x+16-16=21-16

x=5;

(5)4x-2×3=102

4x-6=102

4x-6+6=102+6

4x÷4=108÷4

x=27;

(6)(x+3)÷2=4.5

(x+3)÷2×2=4.5×2

x+3-3=9-3

x=6.