1-39 ODD:
1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37,39
Now you'd add them all up.
1+3+5+7+9 = 25
11+13+15+17+19 = 75
21+23+25+27+29 = 125
31+33+35+37+39 = 175
Add the totals:
25+75+125+175
The answer would be 400.
Answer:

Step-by-step explanation:
let x be the numerator of the rational number then 2x is the denominator
original fraction = 
subtracting 3 from numerator and adding 7 to denominator , gives
=
( cross- multiply )
5(x - 3) = 2(2x + 7) ← distribute parenthesis on both sides )
5x - 15 = 4x + 14 ( subtract 4x from both sides )
x - 15 = 14 ( add 15 to both sides )
x = 29
rational number = 
<h3>
Answer: A) 52 square inches</h3>
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Explanation:
a = 8, b = 13, and c = 15 are the sides of the triangle
s = (a+b+c)/2 = (8+13+15)/2 = 18 is the semi-perimeter, aka half the perimeter.
Those values are then plugged into Heron's Formula below

The triangular plaque has an area of approximately 52 square inches.