1.2X3.4+0.46X0.12+aX2.4=1.2X10
1.2X(3.4+0.046+2a)=1.2X10
3.446+2a=10
2a=6.554
a=3.227
1.2*3.4+0.46*0.12+2.4a=1.2*10
2.4a=12-1.2*3.4-0.46*0.12
a=7.8648÷2.4
a=3.277