Your family goes to a restaurant for dinner. there are 6 people in your family. some order the chicken dinner for $14.80 and some order the steak dinner for $17. if the total bill was $91, how many people ordered each type of dinner?

4 step method:

1.define variables
2.write the systems of equations
3.solve showing all steps
4.state your solution in your sentence

1.)
c=number of people that ordered chicken dinner
s=number of people that ordered steak dinner

2.)
c+s=6
148c+170s=910

3.) 
now you would use elimination or substitution. In this specific problem, i think elimination would be best. Elimination is used to cancel out one variable. For this problem, i will eliminate s.
In order to do that, you need to multiply the top equation by -170 in order to cancel out the positive 170 in the bottom equation. 
-170(c+s=6)
-170c+-170s=-1020

Now, you have 
-170c+-170s=-1020
148c+170s=910

Now you cancel out the s variables and you are left with
-170c=-1020
148c=910

now you add the two equations together
-170c+148c=22c
-1020+910=110

Your new equation is 22c=110

now you divide both sides of the equation by 22 to get c alone

22c/22=110/22

c=5

now you plug in your answer for c in one of the original equations, to make it easier plug it into the top equation 
5+s=6
now subtract 5 from both sides
s=1

5 people bought chicken dinners, and one person ordered steak dinner

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!