How to do this math problem is urgent! The reward is 15! According to the meaning of the question, the volume of rising water is equal to the volume of a cuboid, which can be expressed as:

Flood volume: 20 times 20 times 1.2.

=400 times 1.2

=480 (cubic centimeter)

Height of cuboid: 480/( 12 times 8)

=480/96

=5 cm

Answer: the rectangular stone strip put into the fish tank is 5cm.

Several math problems in senior one! Urgent! Solution:

Let the total stroke be s

The time of a is: T A =2S/[A+B]

The time of b is: TB =1/2s/a+1/2s/b =1/2s [1/a+1/b] =1/2 [a

T A/T B = 2s/[A+B]/[ 1/2s(A+B)/(AB)]= 4ab/[A+B]2

=4AB/[A^2+B^2+2AB]

& lt4AB/[2AB+2AB]

= 1

That is, T A /T B

T a < T b

So, A arrived first.

I just did this problem. ..

Let two be x 1 and x2.

X1x 2 of two different numbers < 0 < 0

The absolute value of negative root is greater than that of positive root, so x 1+x2.