Answer:
10.5 ft.
Step-by-step explanation:
1. Find the radius of the larger circle
4/7 = 3/r --> the ratio should be <em>constant</em>
cross-multiplication: <em>21 = 4r</em>
Divide: <em>r = 5.25 ft.</em>
2. Find the circumference
Equation: <em>C = 2πr</em>
C = <em>2π*5.25</em>
C = 10.5π ft.
Answer:
You are currently 40 years old
Step-by-step explanation:
Let's say the current age is represented by the variable x.
x = current age
The question says that "if you take half my age and add 7, you get my age 13 years ago"
This can be represented like this:
1/2(x) + 7 = x - 13
Now we solve for x using basic algebra:
1/2(x) = x - 20
-1/2(x) = -20
x = 40
To check if this is correct, plug it back into the equation and see if both sides equal each other:
1/2(40) + 7 = (40) - 13
20 + 7 = 27
27 = 27
Hope this helps (●'◡'●)
The quadratic formula is -b + or - the square root of b squared - 4 times the a value and c value over 2a. So the roots would be -1.354249 and -6.645751. I believe these are the roots.