Tìm \(x, y, z\) biết:
a) \(x + 1 = - 2\)
b) \(x:2 = 10:5\)
c) \({\rm{x:2 = y:3}}\) và\({\rm{x + y = 10}}\)
d) \(3x = 2y; 7y = 5z\) và \(x – y + z = 32\)
A.a)\(x = - 3\)
b)\(x = 4\)
c) \(x = 4;y = 6\)
d) \(x = 20;y = 30;z = 42\)
B.a)\(x = - 2\)
b)\(x = 6\)
c) \(x = 6;y = 4\)
d) \(x = 20;y = 40;z = 41\)
C.a)\(x = - 3,5\)
b)\(x = 4,5\)
c)\(x = 2;y = 6\)
d)\(x = 20;y = 30;z = 32\)
D.a)\(x = - 3\)
b)\(x = 4.5\)
c) \(x = 4;y = 5\)
d) \(x = 24;y = 30;z = 42\)