Some chemical formulas contain parentheses. When counting atoms, multiply everything inside the paren- theses by the subscript. For example, Ca(NO3)2 has one calcium atom, two (2 X 1) nitrogen atoms, and six (2 X 3) oxygen atoms. Find the number of atoms of each element in the formu- las Mg(OH)2 and Al2(SO4)3. Record your work in your Science Journal.​

I’m stuck on this i don’t understand.

Given the system of equations presented here: 2x + 4y = 14 4x + y = 20 which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated? multiply the second equation by â’4 to get â’16x â’ 4y = â’80 multiply the second equation by â’1 to get â’4x â’ y = â’20 multiply the first equation by 2 to get 4x + 8y = 28 multiply the first equation by â’1 to get â’2x â’ 4y = â’14

Find the percent cost of the total spent on each equipment $36, fees $158, transportation $59 a. 14%, 62%, 23% b. 15%, 60%, 35% c. 10%, 70%, 20% d. 11%, 62%, 27%