Answer:
45 minutes in all
Step-by-step explanation:
A=45
A=kx/y
where k is constant
substituting the values for k
k= 20×9/6=30
when x=9, y=6
A= 30×9/6=45
Our current equation is:
-8r -31 = -3(5r -6)
To solve for this, we need to get r on one side of the equation and then simplify if needed.
On the right side of the equation, we have a pending Distributive Property, which is when you multiply the number/variable outside of the parenthesis by all numbers/variables in the parenthesis.
Let's simplify this Distributive Property to help understand our equation better.
-3(5r -6)
Multiply -3 by each number/variable separately (unless they are already being multiplied, like 2x, 1/2x, etc).
-3(5r) + -3(-6).
-3(5r) = -15r
-3(-6) = 18 (both negatives need to be in parenthesis to keep a product as negative, and if you do not multiply them in that way, you will end up with a positive product).
Your equation now is:
-8r -31 = -15r + 18
Add 15r to both sides to get r on one side.
7r -31 = 18 is now our current equation.
Add 31 to both sides to get 7r by itself.
7r = 49 is now our equation.
r is still being multiplied by 7, so we need to do the opposite of multiplying by 7.
Divide both sides by 7.
r = 7.
I hope this helps!
Answer:
12.5
Step-by-step explanation:
Answer:
d) 303 8/9
Step-by-step explanation:
4th term = ar^3 and 5th = ar^4 where a = first term and r = common ratio.
So ar^4 / ar^3
= r = 45/-15 = -3.
Working back,:
The first term a = ar^3/ r^3
= -15 / (-3)^3
= -15/-27
= 5/9
Sum of n terms = a * (r^n - 1)/(r-1)
= 5/9 * ((-3)^7 - 1 ) / (-3 -1)
= 303 8/9
