Question 909711
We know the total amount of money invested. $4800
x+y=4800,
We know that the difference in interest earned by the two accounts is $0
0.0485*x-0.031*y=0
x=4800-y
We substitute for x
0.0485*(4800-y)-0.031*y=0
We multiply out
232.8-0.0485y-0.031*y=0
We combine like terms.
232.8=0.0795*y
Isolate y
y=232.8/0.0795
y=2928.30189 at 3.1% 2928 rounded
Calculate x
x=4800-2928.30189
x=1871.69811 at 4.85%  1872 rounded
Interest earned at 4.85% is 90.7773585 rounded 91
Interest earned at 3.1% is 90.7773585 rounded 91
We check
0.0485*1871.69811-0.031*2928.30189=0
90.7773585-90.7773585=0
-0.56843419e-13=0
Since this statement is TRUE and neither x nor y  is negative then all is well