6.9. Сократите дробь: : 3) ; 3a (a + b) 1) 90° (a+b) 10a²b(x - y) 2) 15a4b(x – y) 7a8b3 (a +b) 21a²6% - id2139991620210517 от vika2087 17.05.2021 11:59

Question

Алгебра: 6.9. Сократите дробь: : 3) ; 3a (a + b) 1) 90° (a+b) 10a²b(x - y) 2) 15a4b(x – y) 7a8b3 (a +b) 21a²6% (a+b)? 3(a - b)(a –c) 6(a - b)(a -c) x(y - 3)² 5) x(y-2) 8m(a+b) 6) 4m (a + b) - 3 4) ; -

vika2087 · Accepted Answer

1) {2(x+y) -x =6 ;3x -(x-y) =0 ;
{2x+2y -x =6 ;3x -x+y =0 ;
{x+2y =6 ;2x +y =0 ;
{x+2(-2x) =6 ;y = -2x ;
{x-4x =6 ; y = -2x ;
{ -3x =6 ; y = -2x '
{x = -2 ; y = 4.
ответ : (-2; 4).
* * * x+2y+2x +y =6+0⇔3(x+y)= 6⇔x+y =2 * * *
2) {x+5y = -2 ; 0,5x -y =6.;
{x+5y = -2 ; 2(0,5x -y) =2*6.;
{x+5y = -2 ; x -2y=12 .
{(x+5y) -(x-2y) =-2 -12 ; x -2y=12.
{7y =-14 ; x =2y+12 .
{y = -2 ; x =2*(-2)+12 .;
{y = -2 ; x = 8 .
ответ : (8; -2).
3) {2x+3(x+y) =11; 7(x+3y) - 4y =-23 .
{2x+3x+3y =11; 7x+21y - 4y =-23 .
{5x+3y =11; 7x+17y = -23 .
{17(5x+3y) =11*17 ; -3(7x+17y)  =( -23)*(-3) .
{85x+21y =187 ; -21x+51y  =69 .
{85x+21y -21x+51y  =187+69 ;5x+3y =11.
{64x  =256 ;5x+3y =11.
{x  =4 ;5*4+3y =11.
{x  =4 ;3y =11-20.
{x  =4 ;y =-3.
ответ : (4; -3).

6.9. Сократите дробь: : 3) ; 3a (a + b) 1) 90° (a+b) 10a²b(x - y) 2) 15a4b(x – y) 7a8b3 (a +b) 21a²6% (a+b)? 3(a - b)(a –c) 6(a - b)(a -c) x(y - 3)² 5) x(y-2) 8m(a+b) 6) 4m (a + b) - 3 4) ; -

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