How many hours does it take for the bus and truck to complete the whole journey?
Passenger cars and freight cars walk 1 / 10 per hour, in which passenger cars walk 4 / (4 + 5) = 4 / 9 and freight cars walk 5 / 9
Passenger car per hour (1 / 10) * 4 / 9 = 2 / 45 needs 45 / 2 = 22.5 hours
1 / 10 * 5 * 9 = 1 / 18 takes 18 hours
When the function y = (X-2) (3-x) reaches the maximum, X=______ .
The original quadratic function can be reduced to y = - x2 + 5x-6 = - (X-52) 2 + 14, and the maximum value is x = - B2A = 52
(x^2-3x+2)(x^2-x-6)
-2
The volume of a cylinder is 50 cubic decimeters. If the circumference of its bottom surface is doubled, the height will be reduced to half of the original
What's the volume of a square centimeter? To have a process, please ask how many cubic centimeters
If the perimeter of the bottom surface is increased by 2 times, the area of the bottom surface is increased by 2 × 2 = 4 times
Now the volume of the cylinder is
50 × 4 × 1 / 2 = 100 (cubic decimeter)
It is known that a, B, C, D, e, F, G, h, I, K & nbsp; represent ten different natural numbers greater than 0. To make the following equations hold, the minimum value of a & nbsp; is______ .B+C=A,D+E=B,E+F=C,G+H=D,H+I=E,I+K=F.
Because a = B + C, D + e = B, e + F = C, G + H = D, H + I = e, I + k = f, then a = B + C = D + e + e + F = G + H + 2H + 2I + I + k = G + 3H + 3I + K, because it is known that a, B, C, D, e, F, G, h, I, K represent ten different natural numbers greater than 0, then to make a minimum, that is, G + 3H + 3I + K minimum, only 3H + 3
2x−13−6x−74≥2x+512−1.
4 (2x-1) - 3 (6x-7) ≥ 2x + 5-12; 8x-4-18x + 21 ≥ 2x + 5-12; X ≤ 2
A number to 0 is the same as a number to 100. What's the number
The distance from a number to 0 is the same as that to 100. What is the number
50
Excuse me: given that a and B are opposite to each other, X and y are reciprocal, and C = 2, find the value of [a + b] / 2 + XY-1 / 3 * C
A and B are opposite to each other, a + B = 0x and y are reciprocal to each other, xy = 1lcl = 2, C = 2 or - 2, when C = 2, the above formula = 1-2 / 3 = 1 / 3, when C = - 2, the above formula = 1 + 2 / 3 = 5 / 3
The sum of the subtracted, the subtracted and the difference is 126. The ratio of the difference and the subtraction is 2:5. What is the difference? What is the subtraction?
(process with solution)
If the ratio of difference to subtraction is 2:5, then the subtracted is 2 + 5 = 7,
Then one is: 126 (2 + 5 + 7) = 9
So the subtraction is: 5 × 9 = 45; the difference is 2 × 9 = 18
The subtracted number is: 7 × 9 = 63
If the absolute value of X + 2 + (Y-1) ² = 0, then xy =?
If the absolute value a = 2, then a =?
When s = 1 / 2, B = 1, what is the value of the algebraic formula A & # 178; + 3ab-b & # 178?
If the absolute value of X + 2 + (Y-1) 178; = 0, x + 2 = 0, Y-1 = 0, x = - 2, y = 1, then xy = - 2, if the absolute value of a = 2, then a = ± 2, when a = 1 / 2, B = 1, the value of the algebraic formula A & # 178; + 3ab-b & # 178; = 1 / 4 + 3 / 2 - 1 = (1 + 6 - 4) / 4 = 3 / 4