Answer:
See 2 methods below.
Explanation:
She can do it this way:
Cost of 1 T-shirt = $6
Cost of 4 T-shirts = 4 × $6 = $24
Amount if money she had = $30
Amount of money she has left = $30 - $24 = $6
m = 6
She can also use an equation:
Cost of 4 T-shirts = 4 × 6 = 24
Amount she has left = m
Total amount she had = m + 24
Total amount she had = 30
Equation:
m + 24 = 30
Solve the equation:
m + 24 = 30
Subtract 24 from both sides.
m = 6