1/2. 50 pennies equals $0.50
Answer:
b
Step-by-step explanation:
Looks like this
Everything in one picture
Answer:
D
Step-by-step explanation:
So we have the equation:

And we want to solve for x.
We can solve it by completing the square.
First, subtract 58 from both sides:

Divide the b term by 2 and square it:

So, add 9 to both sides:

On the left, the perfect square trinomial pattern. Add on the right. So:

Take the square root of both sides:

The square root of -49 is 7i:

Add 3 to both sides:

So, our answer is D.
And we're done!
Answer:
r = 4/5
Step-by-step explanation:
Formula
Sum of an infinite geometric series = a / (1 - r)
Givens
Sum = 5*a
a = a
r = ?
Solution
5a = a/(1 - r) Divide both sides by a
5a/a = a / (a * (1 - r) The a's on the right cancel
5 = 1 / (1 - r) Multiply both sides by 1 - r
5*(1 - r) = 1*(1 - r)/(1 - r) The 1 - r s on the right cancel
5*(1 - r) = 1 Remove the brackets.
5 - 5r = 1 Subtract 5 from both sides
5-5 - 5r = 1 - 5 Combine
-5r = - 4 Divide by - 5
r = 4/5