Answer:
Joanna bought 21 items that come out to a total of $33.33. She bought 9 notebooks and 12 pencils.
Step-by-step explanation:
Notebooks (N) = $1.85 Pencils (P) = $1.39
9N+12P= $33.33
9*1.85=16.65
12*1.39=16.68
16.65+16.68=33.33
Answer:
C
Step-by-step explanation:
cot =cos/sin =a/b
cos=a/b*sin
(sin-cos)/(sin+cos) =(sin-sin*a/b)(sin+sin*a/b)
=(1-a/b)/(a+a/b)
=(b-a)/(a+b)
Answer:
D) x=5, x=-5.
Step-by-step explanation:
x^2-25=0
factor
(x+5)(x-5)=0
x+5=0, x-5=0,
x=0-5=-5,
x=0+5=5.
Answer:
2022 students
Step-by-step explanation:
Since 18 out of 270 students speak three or more languages, a prediction would be 30,330 x 18/270 = 2,022 students
The formula for calculating the area of a circle is expressed as;
A = πr²
- Area of the pond = πr²
- Area of the path = Area of the path + pond - area of pond
- Area of path = π(r+1.5)² - πr²
Since the area of the path is equal to the area of the pond, hence;
π(r+1.5)² - πr² = πr²
Add πr² to both sides
π(r+1.5)² - πr² + πr² = πr² + πr²
π(r+1.5)² = 2πr²
(r+1.5)² = 2r²
Expand the parenthesis
r²+3r + 2.25 = 2r²
r²+3r + 2.25 - 2r² = 0
-r² + 3r + 2.25 = 0
r² - 3r - 2.25 = 0
Multiply through by 2
2r² - 6.0r - 4.5 = 0
<em>This proves the required equation</em>
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Learn more on area of composite figures here: brainly.com/question/15981553