Answer:
her weekly allowance is $16
Step-by-step explanation:
Let x represent Joan's weekly paycheck.
Joan spent half of her paycheck going to the movies. This means that the total amount that she spent at the movies is x/2. The amount that she is left with would be
x - x/2 = x/2
She washed the family car and earned 7 dollars. This means that the total amount left with her is
x/2 + 7
if she ended with 18 dollars, it means that
x/2 + 7 = 18
x/2 = 18 - 7 = 11
x = 2 × 11 = $22
