0.2(d-b)=0.3b+5-3+0.1d
you first distribute the 0.2 to the d and b in the parentheses, you'll then get
0.2d-0.2b=0.3b+5-3+0.1d
now you make sure that the b variables are with each other on the same side of the equal sign. so you subtract 0.3b from both sides to get
0.2d-0.5b=5-3+0.1d
now do the same thing with the d variables so subtract 0.1d from both sides to get
0.1d-0.5b=5-3
now you can subtract 5-3 which is easy to get
0.1d-0.5b=2
now you have to figure out what d and b equal. so i'll do b first. all you do is use the equation you have now and pretend that d is 0 so substitute the 0 in with the d variable to get
0.1(0)-0.5b=2
now you divide -0.5b from both sides to get
-0.5b/-0.5= b 2/-0.5= -4
so now you know b = -4
now you do sthe sane thing with b substitute with a 0 to get
0.1d-0.5(0)=2
then divide 0.1d from both sides to get
0.1d/0.1=b 2/0.1=20
now you know d = 20
( d=20, b=-4 )
