When reading problems, certain words can act as “road-signs” to writing equations.
Example: Write the described inequality
Key words: 5 less, twice a number, greater
Equations from story problems:
At a talent show, adult tickets are $7 and child tickets are $5. If 87 tickets are sold and $571 are made from ticket sales, how many of each type of ticket were sold?
Equation 1) 87 tickets sold
A + C = 87
Equation 2) Price of each ticket, total amount of profit from ticket sales
$571 = profit from child tickets + profit from adult tickets
$571 = A($7) + C($5)
2 variables and 2 equations → solvable system