Answer:
$3.99 per watermelon
Step-by-step explanation:
$39.90 total paid divided by 10 watermelons is $3.99
3(5b-1)=5
Get rid of the brackets
15b-3=5
add 3 to both sides of the equation
15b=8
divide both sides of the equation by 15
b=0.53
4(3y-1)=20
12y-4=20
12y=24
y=0.5