<=>x-3=0(vì cái kia >0 với mọi x)

<=>x=3

=>x-3=0

hay x=3

<=> ( x + x + x + .... + x + x ) + ( 1 + 2 + 3 + .... + 49 + 50 ) = 1425

<=> 50x + { [ 50.( 50 + 1 ) ] : 2 } = 1425

=> 50x + 1275 = 1425

=> 50x = 1425 - 1275

=> 50x = 150

=> x = 150 : 50 = 3

=> (x+ x+ x +...+ x) + (1+2+..+ 50) = 1425

=> 50x + 1275=1425

=> 50x = 150

=> x=3

**** mk nha!

<=>(x+x+...+x)+(1+2+3+...+50)=1425

=>50x+1275=1425

=>50x=1425-1275

=>50x=150

=>x=3

27 = 3^x

=> 3³ = 3^x

=> x = 3

27 = 3^x

3^x = 3³

x = 3

Chúc bạn học tốt ^^

27 = 3^x
27 = 3³
  x = 3

p=1 nha

(9+1)+(8+2)+(7+3)+(6+4)+10+5

=10+10+10+10+10+5=45

9+3+2+1+7+8+5+10+6+4= (9+1)+(2+8)+(3+7)+(4+6)+5=10+10+10+10+5=10.4+5=40+5=45

(9+1)+(3+7)+(2+8)+(6+4)+10

=10+10+10+10+10

=50

\(\frac{3}{5}.x-x=\frac{-4}{15}\)

<=>\(x.\left(\frac{3}{5}-1\right)=\frac{-4}{15}\)

<=>\(\frac{-2}{5}.x=\frac{-4}{15}\)

<=>\(x=\frac{-4}{15}:\frac{-2}{5}\)

<=>\(x=\frac{2}{3}\)

vậy \(x=\frac{2}{3}\)

Ta có:\(\frac{3}{5}.x-x=-\frac{4}{15}\)

\(\left(\frac{3}{5}-1\right).x=-\frac{4}{15}\)

\(\left(\frac{3}{5}-\frac{5}{5}\right).x=-\frac{4}{15}\)

\(\left(-\frac{2}{5}\right).x=-\frac{4}{15}\)

\(x=-\frac{4}{15}:\left(-\frac{2}{5}\right)\)

\(x=-\frac{4}{15}.\left(-\frac{5}{2}\right)\)

\(x=\frac{\left(-4\right).\left(-5\right)}{15.2}\)

\(x=\frac{20}{30}=\frac{2}{3}\)

\(=\left(15\frac{2}{3}+12\frac{1}{3}\right):3-\frac{8}{3}\)

\(=28:3-\frac{8}{3}\)

\(=\frac{28}{3}-\frac{8}{3}\)

\(=\frac{20}{3}\)

\(15\frac{2}{3}:3+12\frac{1}{3}:3-\frac{8}{3}\)

\(=\left(15\frac{2}{3}+12\frac{1}{3}\right):3-\frac{8}{3}\)

\(=28:3-\frac{8}{3}\)

\(\frac{28}{3}-\frac{8}{3}\)

\(\frac{20}{3}\)