Question

Bài 1 tìm x

a)30+X=120÷5+27

b)40-3×X=13

c)2×X-8=16

d)1/2×X-1/3=1/4

 Giúp em với ạ

Answer 1

\(a,30+X=120:5+27\\ 30+X=24+27\\ 30+X=51\\ X=51-30=21\\ ---\\ b,40-3\times X=13\\ 3\times X=40-13=27\\ X=\dfrac{27}{3}=9\\ ---\\ 2\times X-8=16\\ 2\times X=16+8\\ 2\times X=24\\ X=\dfrac{24}{2}=12\\ \\---\\ \dfrac{1}{2}\times X-\dfrac{1}{3}=\dfrac{1}{4}\\ \dfrac{1}{2}\times X=\dfrac{1}{4}+\dfrac{1}{3}=\dfrac{7}{12}\\ X=\dfrac{7}{12}:\dfrac{1}{2}=\dfrac{7}{6}\)

Answer 2

a.30+X=24+27

30+X=51

      X=51-30

       X=21

b.3xX=40-13

3xX=27

   X=27:3=9

C.2xX=16+8

2xX=24

 X=24:2=12

D.1/2xX=1/3+1/4

1/2xX=7/12

     X=7/12:1/2=7/6

Answer 3

a) \(30+x=120:5+27\)

\(30+x=24+27\)

\(30+x=51\)

\(x=51-30\)

\(x=21\)

_____

b) \(40-3\times x=13\)

\(3\times x=40-13\)

\(3\times x=27\)

\(x=27:3\)

\(x=9\)

______

c) \(2\times x-8=16\)

\(2\times x=16+8\)

\(2\times x=24\)

\(x=24:2\)

\(x=12\)

______

d) \(\dfrac{1}{2}\times x-\dfrac{1}{3}=\dfrac{1}{4}\)

\(\dfrac{1}{2}\times x=\dfrac{1}{4}+\dfrac{1}{3}\)

\(\dfrac{1}{2}\times x=\dfrac{7}{12}\)

\(x=\dfrac{7}{12}:\dfrac{1}{2}=\dfrac{7}{12}\times2\)

\(x=\dfrac{7}{6}\)

 

Answer 4

a, 30+x= 120:5+27

30+x= 25+27

30+x =52

x=52-30

x=22

 

b, 40-3xX=13

3xX=40-13

3xX=27

X=27:3

X=9

c,2xX-8=16

2xX=16-8

2xX=8

X=8:2

X=4

d,1/2xX-1/3=1/4

1/2xX=1/4+1/3

1/2xX=7/12

X=7/12: 1/2

X=7/6