Ta có:

x*62+x*48=4200.

x*(62+48)=4200.

x*110=4200.

x*11=420.

x=420/11.

Vậy x=420/11.

X x 62 +X x 48=4200

(62+48)x X     =4200

110 x X         =4200

         X        =4200:110

        X        =38,18

k nha

X x 62 + X x 48 = 4200 

X x ( 62 + 48 )   = 4200

X x 110             = 4200

X                      = 4200 : 110

X                      = \(\frac{420}{11}\)

~ Chúc học tốt ~

Ai ngang qua xin để lại 1 L - I - K - E 

X x 62 +X x 48 = 4200

=> X x (62+48)=4200

=> X x 110=4200

=> X=4200:110

=> X=\(\frac{420}{11}\)

Xx62+Xx48 = 4200

Xx(62+48)=4200

Xx110=4200

X=4200:110

X=38(18)

X×62+X×48=4200

X×(62+48)=4200

X×110=4200

X =4200:110

X=\(\frac{420}{11}\)

X×62+X×48=4200

\(x\times\left(62+48\right)=4200\)

\(x\times110=4200\)

\(x=4200:110\)

\(x=\dfrac{420}{11}\)

X x 62 + X x 48= 4200

X x(62 + 48)= 4200

X x 110= 4200

X = 4200 : 110

X = 4200/ 110= 420/ 11

Dxw6d

\(\dfrac{x^2-3xy+y^2}{x+y+2}=\dfrac{\left(3+\sqrt{5}\right)^2+3\left(3+\sqrt{5}\right)\left(3-\sqrt{5}\right)+\left(3-\sqrt{5}\right)^2}{3+\sqrt{5}+3-\sqrt{5}+2}=\dfrac{9+2\cdot3\sqrt{5}+5+3\left(9-5\right)+9-2\cdot3\cdot\sqrt{5}+5}{8}=\dfrac{40}{8}=5\)

có nhận ra tớ không 

x * 62 + x * 48 = 4200

x*(62+48)=4200

x*100=4200

x       =4200:100

x       =42

Mình cho x là y cho dễ nhớ.  

y x 62 + y x 48 = 4200 

y x ( 62 + 48 ) = 4200              

y x 110 = 4200 

y          = 4200 : 110

y          =  420/ 11

 Mình ko chia hết được nhé 

Ta có : \(\frac{6}{11}x=\frac{9}{2}y\)=> \(\frac{12x}{22}=\frac{99y}{22}\)=> 12x = 99y => 4x = 33y => \(\frac{x}{33}=\frac{y}{4}\)

\(\frac{9}{2}y=\frac{15}{5}z\)=> \(\frac{45y}{10}=\frac{30z}{10}\)=> 45y = 30z => 3y = 2z => \(\frac{y}{2}=\frac{z}{3}\)

=> \(\frac{x}{33}=\frac{y}{4};\frac{y}{2}=\frac{z}{3}\)

=> \(\frac{x}{66}=\frac{y}{4};\frac{y}{4}=\frac{z}{12}\)

=> \(\frac{x}{66}=\frac{y}{4}=\frac{z}{12}\)và y - x + z = -120

Áp dụng t/c dãy tỉ số bằng nhau ta có :

\(\frac{x}{66}=\frac{y}{4}=\frac{z}{12}=\frac{y-x+z}{4-66+12}=\frac{-120}{-50}=\frac{12}{5}\)

=> \(\hept{\begin{cases}\frac{x}{66}=\frac{12}{5}\\\frac{y}{4}=\frac{12}{5}\\\frac{z}{12}=\frac{12}{5}\end{cases}}\)=> \(\hept{\begin{cases}x=\frac{792}{5}\\y=\frac{48}{5}\\z=\frac{144}{5}\end{cases}}\)

x=0;y=-5

x=-4;y=-1

x=-2;y=1

x=2;y=-3