The side length of the green belt is x.
x^2/30^2=2
x=30√2=42.43
The side length of the green belt is 42.43 meters. Question 2. The three sides of the triangle are 13, 14 and 15 respectively. What is the area of this triangle? The answer is given by Helen's formula: p = (13+14+15)/2 = 21.
s =√p(p-a)(p-b)(p-c)= √[ 2 1(2 1- 13)(2 1- 14)(2 1- 15)]= 84
Question 3. In quadrilateral ABCD, ∠ B = 90, AB = 3, BC = 4, CD = 12, AD = 13, what is the area of quadrilateral ABCD? Answer 3, AC=5, and the triangle ADC is a right triangle, so the area is 3 * 4/2+5 * 12/2 = 36.
Question 4. When asked what the value of x is, the value of equation 9X 2+23x-2 is the product of two consecutive even numbers.
The answer x = {-23+-[601+144k (k+1)] (1/2)}18.
Where k = 0, 1, 2, 3, 4, ... especially when k=4.
X = (-23 +- 59)/ 18 = 2 or -4 1/9-.
When asked what the value of x is, the value of equation 9X 2+23x-2 is the product solution of two consecutive even numbers: the value of equation 9X 2+23x-2 is the product of two consecutive even numbers, so equation 9X 2+23x-2 = 0 has two consecutive even numbers.
Suppose these two even numbers are 2k and 2 (k+ 1), k >；; =0, and k is an integer 9x 2+23x-2 = 2k * 2 (k+ 1).
9x 2+23x-(2+2k * 2 (k+ 1)) = 0 discriminant
23^2 + 4*9*(2 + 2k*2(k+ 1))
= 23^2 + 72( 1 + 2k(k+ 1))
= 23^2 + 72 + 144k(k+ 1)
= 60 1+ 144k(k+ 1)>= 0k^2+k+60 1/ 144 & gt； =0
(k+ 1/2)^2- 1/4+60 1/ 144 & gt； =0
60 1/ 144 - 1/4 〉0
So when k is an arbitrary integer, 601+144k (k+1) > = 0 is true! So x = {-23+-[601+144k (k+1)] (1/2)}18.
Where k = 0, 1, 2, 3, 4, ... especially when k=4.
X = (-23 +- 59)/ 18 = 2 or -4 1/9 Question 5. At first, two employees of Party A and Party B accepted the same production task. At first, Party B made four pieces less than Party A every day and two days more than Party A, leaving 624 pieces per person. Subsequently, Party B improved the production technology and produced more than before. What is everyone's total production task? A: The overall task is N;
At first, A made X pieces every day for y-2 days.
Then b makes x-4 pieces every day for y days. x(y-2)=(x-4)y = n-624；
X=2y，2y ^ 2-4y = n-624。
Later, A made X pieces every day, z+2 days;
Then b makes x+2 pieces every day for z days. X(z+2)=(x+2)z=624，
X=z，x 2+2x = 624。 The results show that x=24, y= 12, z=24, n=864. Conclusion Party A and Party B produce 24 pieces and 20 pieces per day respectively.
Everyone's total production task is 864 pieces, please accept, thank you! !