Question

tìm tự nhiên x biết

a) 123 - 5 : (x +4) =38

b)70 -5 x (x - 3 )=45

c)10 +2 x x =4^5 : 4^3

d ) 2 x x - 138 = 2^3 x 3^2

giúp mik với mik đang cần vào ngày maisuy nghi nha

Answer 1

a)\(123-5:\left(x+4\right)=38\)

\(5:\left(x+4\right)=123-38\)

\(5:\left(x+4\right)=85\)

\(x+4=5:85\)

\(x=\dfrac{1}{17}-4\)

\(x=-\dfrac{67}{17}\)

Answer 2

b)\(70-5.\left(x-3\right)=45\)

\(5.\left(x-3\right)=70-45\)

\(5.\left(x-3\right)=35\)

\(x-3=35:5\)

\(x-3=7\)

\(x=7+3\)

\(x=10\)

Answer 3

c)\(10+2.x=4^5:4^3\)

\(10+2.x=4^{5-3}\)

\(10+2.x=4^2=16\)

\(2.x=16-10\)

\(2.x=6\)

\(x=6:2\)

\(x=3\)

Answer 4

d)\(2.x-138=2^3.3^2\)

\(2.x-138=8.9\)

\(2.x-138=72\)

\(2.x=72+138\)

\(2.x=210\)

\(x=210:2\)

\(x=105\)