Выражение а) -6ху^7 ×3х^3у^5 б) (-5а^4б^2)^3 годовая​

В)  =x(x+3)/(x-3)² : (  3/(x+3) +(x² +9)/(x² -9) +3/(x-3) ) = x(x+3)/(x-3)²  : ( (3(x-3) +x ²+9 +3(x+3))  /(x -3)(x+3)  ) = x(x+3)/(x-3)²  : (  (  x ²+6x +9)  /(x -3)(x+3)  )  =x(x+3)/(x-3)²    : (  (  x+3)²  /(x -3)(x+3)  )  = x(x+3)/(x-3)²    *  (x -3)/(x+3)  =x/(x-3). a)  (  (x+5y)/(x² --5y)/(x² -5y)  )* 5y²/(25y² -x²) =50y³/(x² -5y)(25y² -x²) . б) ( (a -2b)/a(a+2b) -(a+2b)/a(a-2b) ) * (4b² -a²)/4b²   =   -2b)² -(a+2b)²  )  /a(a² -  4b²) )*  (4b²  -a²)/4b²   =( 8b/(4b²  -a²))  )*  (4b²  -a²)/4b² =  2  /  b. г)   = ( c/(c-2) -c/(c+2) +(c²+4)/(c² -  4) ) *(c-2)²/c(c+2) = ( c² +2c -c² +2c +c² +4)/(c-2)(c+2) )  *(c-2)²/c(c+2)  = ( (c +2)²/(c-2)(c+2) ) *  (c-2)²/c(c+2)   =(c-2) / c.     ||   1 -2/c ||

z = 6 - 5x - 6y

y = 7 - 6z - 5x

z = 4x + 3y - 4

 

z = 6 - 5x - 6y

y = 7 - 6(6 - 5x - 6y) - 5x

6 - 5x - 6y  = 4x + 3y - 4

 

z = 6 - 5x - 6y

y = 7 - 36 + 30x + 36y - 5x

10 - 9x   = 9y

 

z = 6 - 5x - 6y

29 = 25x + 35y

10/9 - x   = y

 

z = 6 - 5x - 6y

29 = 25x + 35(10/9 - х)

10/9 - x   = y

 

z = 6 - 5x - 6y

29 = 25х + 350/9 - 35x

10/9 - x   = y

 

z = 6 - 5x - 6y

10х = 89/9

10/9 - x   = y

 

z = 6 - 5x - 6y

x = 89/90

10/9 - 89/90   = y

 

z = 6 - 5x - 6y

x = 89/90

y = 11/90

 

z = 6 - 5*89/90 - 6*11/90

x = 89/90

y = 11/90

 

z = 29/90

x = 89/90

y = 11/90

 

всё верно