The parentheses group 3 and 2 together and 6 and 4 together and the square brackets tell us to do all the calculations inside them before multiplying by 4. 1 3 36 9 2 2. Now you can get rid of the parentheses altogether.
When you see a math problem containing parentheses you need to use the order of operations to solve it.
You must remember to multiply the subscripts of atoms inside the parentheses by the subscripts outside the parentheses. The first thing to evaluate there is the exponent 6 2. Click to see full answer. FeNO_3_2 Na_3PO_4 Fe_3PO_4_2 NaNO_3.