Question 1165810
let x equal the amount invested at 20%.
let y equals the total amount invested which equals his bonus.


your formulas become:
25000 + x = y
.16 * 25000 + .20 * x = .19 * y


since y = 25000 + x, then your second equation becomes:
.16 * 25000 + .20 * x = .19 * (25000 + x).
simplify this equation to get:
4000 + .20 * x = 4750 + .19 * x
subtract 4000 from both sides of this equation and subtract .19 * x from both sides of this equation to get:
.20 * x - .19 * x = 4750 - 4000
combine like terms to get:
.01 * x = 750
solve for x to get:
x = 750 / .01 = 75000


you have x = 75000
this makes 25000 + x = y become 25000 + 75000 = 100,000


to confirm these values are good, replace the variables in the original equation with them to get:
25000 + 75000 = 100,000
.16 * 25000 + .20 * 75000 = 4000 + 15000 = 19000
19000 / 100,000 = .19 * 100 = 19%.


solution looks good.
solution is:
he invested 75000 at 20% and his total bonus was 100,000.