Suppose he invest x dollars in one account, y in the other
x+y=12,500
0.042x+0.062y=669.50
multiple the first equation by 0.042: 0.042x+0.042y=525
subtract this new equation from equation 2: 0.02y=144.50
y=7225
x=12500-7225=5275
Answer: twenty one decreased by eighteen or the difference of twenty one and eighteen
H is 6. If you are not familiar with /3 you could time the whole equation by 3
