Answer:
The simplified expression is given as

Step-by-step explanation:
step one:
Given the expression

step two:
First, let us open the bracket we have

step three:
collect like terms we have

step four:
we can now factor out
we have

Answer: 63 nurses and 14 doctors
so you know the ratio is 9:2. that means for every 9 nurses there are 2 doctors. i didn't make an equation but i counted it.
if theres 9 (9*1) nurses theres 2 (2*1) doctors
if theres 18 (9*2) nurses theres 4 (2*2) doctors
if theres 27 (9*3) nurses theres 6 (2*3) doctors
you get the point so i multiplied 7 to 9 and 7 to 2, which means:
if theres 63 (9*7) nurses theres 14 (2*7) doctors
i hope this helps :)
You can do all strategies. Multiplication, Division, Addition, and Subtraction are the strategies because you can multiply 7 by 4 to get 28, divide 56 by 2 to get 28, add 14 by 14 to get 28, or subtract 40 by 12 to get 28.
The complement would be 90-23 which is 67