-15/49
Объяснение:
(2,8а+1/14-7а^4)-(0,7а-4/7-7а^4)=0
2,8а+1/14-7а^4-0,7а+4/7+7а^4=
=(2,8-0,7)а+(1/14+4/7)+а^4(-7+7)=
=2,1а+1/14+8/14+0=
=2,1а+9/14=0
2,1а=-9/14
а=-(9/14):(2,1)=-(9/14)*(10/21)=
=-(3*3*2*5)/(2*7*3*7)=
=-(3*5)/(7*7)=-15/49
-15/49
Объяснение:
(2,8а+1/14-7а^4)-(0,7а-4/7-7а^4)=0
2,8а+1/14-7а^4-0,7а+4/7+7а^4=
=(2,8-0,7)а+(1/14+4/7)+а^4(-7+7)=
=2,1а+1/14+8/14+0=
=2,1а+9/14=0
2,1а=-9/14
а=-(9/14):(2,1)=-(9/14)*(10/21)=
=-(3*3*2*5)/(2*7*3*7)=
=-(3*5)/(7*7)=-15/49
Объяснение: