Answer:
7
Step-by-step explanation:
If J is Joan's current age and E is Ellen's current age, then:
J = E + 5
(J - 3) + (E - 3) = 17
Solve the first equation for E:
E = J - 5
Substitute into the second:
(J - 3) + (J - 5 - 3) = 17
J - 3 + J - 8 = 17
2J - 11 = 17
2J = 28
J = 14
Joan is 14, so in 7 years, she will be 21.
So you can round 3.9 to 4, and 5.3 to 5. so 4x5=20. there would then be 2 digits in front of the decimal point. (:
Answer:

Step-by-step explanation:
You know that
and have to find

Use the main properties of exponents:
1. 
2. 
Note that

then

Now

Since
then 
divide the total weight by the number of piles
9/5 = 1.8 pounds per pile
Answer:
One real root, with multiplicity 7.
Step-by-step explanation:
The given expresion is

This is a seventh degree polynomial.
According to the fundamental theorem of Algebra, the expression has a potential 7 roots both real and complex.
This expression has one real root, with multiplicity , 7.