Answer:
Last year earning were $22,300
Explanation:
The equation is given which is that Mrs. Hernandez saves 4% and earned $200 more and she saved $900.
Equation
0.04 (x +200) = 900
Solving the equation
0.04x + 8 = 900
0.04x = 900 -8
0.04x = 892
X = 892/ 0.04
X = 22,300
Hence, her last year earning were $22,300