Answer:
Part 1) Helen's age is 32 years old and Jane's age is 24 years old
Part 2) 13 twenty-dollar bills
Step-by-step explanation:
Part 1) Helen is 8 years older than Jane. Twenty years ago Helen was three times as old as Jane. How old is each now and what is the equation?
Let
x----> Helen's age
y---> Jane's age
we know that
x=y+8 ----> equation A
(x-20)=3(y-20) -----> equation B
substitute equation A in equation B and solve for y
(y+8-20)=3(y-20)
y-12=3y-60
3y-y=60-12
2y=48
y=24 years
Find the value of x
x=y+8
x=24+8=32 years
Part 2)
Let
x-----> the number of five-dollar bills
y----> the number of twenty-dollar bills
we know that
5x+20y=305 -----> equation A
y=x+4 ------> x=y-4 ------> equation B
substitute equation B in equation A and solve for y
5(y-4)+20y=305
5y-20+20y=305
25y=325
y=13 twenty-dollar bills
Find the value of x
x=y-4
x=13-4=9 five-dollar bills
Answer:
43.9823
Step-by-step explanation:

Well let's see.
If the figure is split up into 10 pieces, then
each piece is 1/10 of the whole figure.
If 2 of the pieces are shaded, then
2/10 of the whole figure is shaded.
How many pieces are left ?
There were 10 pieces all together, and
2 of them are shaded. Hmmm. I think
there are probably (10 - 2) = 8 of them left
that are not shaded.
8 pieces makes 8/10 of the whole figure.
Step-by-step explanation:
A,true
doesn't interfere with any function restriction
3(y-7)
use distributive property