In this equation: febr2+k2co3=fe2(co3)2+kbr do i simplify the 2's on iron and the co3 on the "right side" before continuing or keep them and why?

Determine the rate law, including the values of the orders and rate law constant, for the following reaction using the experimental data provided. a + b yields products trial [a] [b] rate 1 0.30 m 0.25 m 1.2 × 10-2 m/min 2 0.30 m 0.50 m 4.8 × 10-2 m/min 3 0.60 m 0.50 m 9.6 × 10-2 m/min