Story and Word Problems

When reading problems, certain words can act as “road-signs” to writing equations.

Example: Write the described inequality

• 5 less than twice a number is greater than 42.

Key words: 5 less, twice a number, greater

• twice a number → 2×
• 5 less → 2× – 5
• greater than → 2× – 5 > 42

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?

Define variables:

• # of adult tickets → A
• # of child tickets → C

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