\(x\)x12.25-\(x\)+\(x\)x 2.75=1050

\(x\)x ( 12,25 - 1 + 2,75 ) = 1050

\(x\)x 14 = 1050

\(x\)= 1050 : 14

\(x\)= 75

Vậy \(x\)= 75

# HOK TỐT #

Ta có : X*12.25-X+X*2.75=1050

            X (12.25-1+2.75)=1050

             X*14=1050

             X=75

Vậy X=75

# chúc cậu học tốt #

minh ko biet

Đề em ơi

Ta có: \(4,25\cdot17+4,25\cdot53+4,25\cdot30\)

\(=4,25\cdot\left(53+17+30\right)\)

=425

12,5+x:0,25-2,25=12,25

x:0,25=12,25+2,25-12,5

x:0,25=2

x      =2x0,25

x       =  0,5

12,5+x:0.25-2.25=12.25

x : 0,25 = 12,25 + 2,25 - 12,5

x : 0,25 = 2

x          = 2 x 0,25

x          = 0,5

\(\frac{5.18-10.27+15.36}{10.36-20.54+30.72}\)

\(=\frac{5.18-\left(5.2\right).27+\left(5.3\right).36}{\left(5.2\right).36-\left(5.4\right).54+\left(5.6\right).72}\)

\(=\frac{5.18-5.\left(2.27\right)+5.\left(3.36\right)}{5.\left(2.36\right)-5.\left(4.54\right)+5.\left(6.72\right)}\)

\(=\frac{5.18-5.54+5.108}{5.72-5.216+5.432}\)

\(=\frac{5.\left(18-54+108\right)}{5.\left(72-216+432\right)}\)

\(=\frac{5.\left(-36+108\right)}{5.\left(-144+432\right)}\)

\(=\frac{5.72}{5.288}\)

\(=\frac{5.72}{5..4.72}\)

\(=\frac{1}{4}\)

giúp  mik với

rut gọn ak

4,25 x 57,43 – 325 + 42,57 x 4,25 

\(=244,0775-325+180,9225\)

\(=100\)

\(\overline{M_A}=45\)

\(\%N=100\%\left(53,33\%+15,56\%\right)=31,11\%\)

Gọi CT: CxHyNt

x : y : t = \(\dfrac{53,33}{12}:\dfrac{15,56}{1}:\dfrac{31,11}{14}\)

           =  2         : 7         : 1

=> CT: \(\left(C_2H_7N\right)_n\)

n = 45:45 = 1

=> \(C_2H_7N\)

B)

\(\overline{M_X}=30\)

%H = 20%

Ta có:   x : y = \(\dfrac{80}{12}:\dfrac{20}{1}\)

                   =  1   : 3

\(\Rightarrow\left(CH_3\right)_n\)           \(\Rightarrow n=\dfrac{30}{15}=2\)

\(\Rightarrow C_2H_6\)