Question

a, [( 6 . x - 39 ) .7 ] .4 =12

b, 200 - ( 2 . x + 6 ) = 4³

c, 3² . ( x + 4 ) -  5² = 5. 2²

mn giúp em vs,đang cần gấp ạ 

 

Answer 1

\(a.\left[\left(6.x-39\right).7\right].4=12\)

\(\left(6.x-39\right).7=12:4\)

\(6.x-39=3:7\)

\(6.x=\frac{3}{7}+39\)

\(x=\frac{276}{7}:6\)

\(x=\frac{46}{7}\)

( câu a )

Answer 2

\(b.200-\left(2.x+6\right)=4^3\)

\(200-\left(2.x+6\right)=64\)

\(2.x+6=200-64\)

\(2.x=136-6\)

\(x=130:2\)

\(x=65\)

( câu b )

Answer 3

\(c.3^2.\left(x+4\right)-5^2=5.2^2\)

\(9.\left(x+4\right)-25=5.4\)

\(9.\left(x+4\right)-25=20\)

\(9.\left(x+4\right)=20+25\)

\(x+4=45:9\)

\(x=5-4\)

\(x=1\)

( câu c )

~HT~