Don't quote me but i'm pretty sure it is a right triangle
-2(2b-3)
Multiply the bracket by -2
Whenever multiplying a -negative number with a -negative number= + positive number.
(-2)(2b)(-2)(-3)
-4b+6
Answer: -4b+6
Write a recursive and explicit formula for each option.
Save a nickel on the first day of the month and then double the amount each day for a month
=> a1 =0.05
=> a2 = a1* 2 = 0.05*2
=> a3 = a2*2 = a1* 2*2
..............................................
=>recursive an =
=> explicit an = 0.05*
Start their savings by saving $10 on the first day and then $10 each day of the month
=> a1 = 10
=> a2 = a1 + 10 = 20
=> a3 = a2 +10 = 20 +10 =30
........................................................
=> recursive an = 
=> explicit an = 10 + 10( n-1)
Hope it will find you well.
The price of of the hotdog to the price of popcorn is in the ratio 5:4
25:20 is 5:4
The two in the hundredths place is ten times less than the two in the tenths place.