40 170,000,000,000
----- = --------------------------
100 x
Multiply diagonally to solve
So you get 40x = 17,000,000,000,000
Then divide each side by 40 to get x alone
So the answer is 42,500,000,000,000
-kxy=4x^2-9y^2
-kx=(4x^2/y)-9y
-k=4x/y-9y
k=-4x/y+9y
So, this sum divided by 4 was 189.5... then if we multiply this number by 4, we will get this sum!
189.5*4=758
which is the sum of two consecutive even numbers, x and x+2,
x+x+2=758
2x+2=758
2x=756
x=378
and the other number is 380!!
Step-by-step explanation:
AB = DC = 40 - 2x
AD = BC = 30 - 2x
there is not more explanation possible, I think.
we cut off from each side 2 pieces of x cm. so, AB, DC, AD, BC are the the remaining lengths.
the volume of the box is ground area times height (x is the length of the remaining flaps after the cut, so, when folding up these flaps/sides, they will be x cm high).
Volume = y = AB×AD×x
=> y = (40-2x)×(30-2x)×x = (1200 - 60x - 80x + 4x²)×x =
= (1200 - 140x + 4x²)×x = 4x³ - 140x² + 1200x
