(1)(x+12)×4/5=42-x
4(x+12)=5(42-x)
4x+48=210-5x
4x+5x=210-48
9x=162
x=18
(2)1又5分之3除以(x-0.45)=5分之16;
(1+3/5)÷(x-0.45)=16/5;
x-0.45=(8/5)×(5/16)=1/2;
x=0.5+0.45;
x=0.95;
(1)(x+12)×4/5=42-x
4(x+12)=5(42-x)
4x+48=210-5x
4x+5x=210-48
9x=162
x=18
(2)1又5分之3除以(x-0.45)=5分之16;
(1+3/5)÷(x-0.45)=16/5;
x-0.45=(8/5)×(5/16)=1/2;
x=0.5+0.45;
x=0.95;