X= first integer
21-x= second integer
(x)(21-x)= 108
multiply x by each term in parentheses
21x - x^2= 108
subtract 108 from both sides
21x - x^2 - 108= 0
-x^2 + 21x - 108= 0
multiply whole equation by -1 to eliminate the negative coefficient in the first term
(-1)(-x^2 + 21x - 108)= 0
x^2 - 21x + 108= 0
factor (remember we need #s to add to 21 and multiply to 108)
(x-12)(x-9)= 0
x-12= 0
x= 12
x-9= 0
x= 9
CHECK:
9 + 12= 21
9 * 12= 108
ANSWER: The two positive integers that add to 21 and multiply to 108 are 12 and 9.
Hope this helps! :)
Answer:
k = 0
Step-by-step explanation:
-2k = 8k + 7k
Add similar elements:
-2k = 15k
Subtract 15k from both sides:
-2k - 15k = 15k - 15k
Simplify:
-17k = 0
Divide both sides by -17:
17k/-17 = 0/-17
k = 0
I wasn't sure if you wanted me to solve for k or combine the like terms.
Area of a circle = pi * r^2
Radius (r) = ½ * diameter
½ * 10 = 5
A= pi * 5^2
25 * pi = 78.54 sq inches
10.99 / 78.54 = about 14 cents per sq in (13.99)
Answer:
36π
Step-by-step explanation: