Answer:
let the amount deposited by each of them in march be m. 
in April, Isaiah deposited 210$, this means the amount in his account became m+210 
Freddie increased the amount by 15%, this means that the amount of money in his account became: m+0.15m 
since both values are still equal, we will equate both equations and solve for m. 
m+210 = m+0.15m 
0.15m = 210 
m = 1400$
Explanation: