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Number a is 20, number B is 25. 1. What percentage is number B? 2. What percentage is number a less than number B? 3. What percentage is number B more than number a? 4. What's the percentage of the sum of a, B, two numbers? Quick! Clear answer, don't give me the answer directly, and don't omit the middle of the formula^
Number a is 20, number B is 25
What's the percentage of B to a?
25 / 20 = 125 / 100 = 125%
B is 125% of A
What percentage is a less than B? What percentage is B more than a?
25 - 20 = 5
5 / 25 = 20 / 100 = 20%
5 / 20 = 25 / 100 = 25%
The number a is 20% less than the number B, and the number B is 25% more than the number a
What percentage of the sum of a and B?
20 + 25 = 45
20 / 45 = 4 / 9 = 0.44 = 44%
The number a is 44% of the sum of two numbers
-/A / must be negative, right
No, maybe 0
It must be a non positive number
The sum of the three numbers is 120, the number a is twice that of the number B, the number C is 20 more than the number B, and the number C is 120___ ．
Let B number be x, then a number be 2x, C number be x + 20.2x + X + X + 20 = 120 & nbsp; & nbsp; & nbsp; 4x + 20 = 120 & nbsp; 4x + 20-20 = 120-20 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 4x = 100 & nbsp; & nbsp; & nbsp; & nbsp; 4x △ 4 = 100 △ 4 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 25.25 + 20 = 45
Given that 0 ＜ α ＜ π 2, the equation x2sin α + y2cos α = 1 represents an ellipse with focus on the y-axis, then the value range of α is obtained______ ．
The equation x2sin α + y2cos α = 1 is reduced to the standard form: x21sin α + y21cos α = 1. ∵ the equation represents the ellipse with the focus on the Y axis, ∵ 1cos α > 1sin α > 0, the solution is sin α > cos α > 0 ∵ 0 ∵ α < π 2, ∵ π 4 ∵ α < π 2, that is, the value range of α is (π 4, π 2), so the answer is: (π 4, π 2)
If a number is reduced by 60%, it will be 2 / 3 of 120
x-x*60%=120*2/3
x=200
Let a and B be m * n matrices, and R (a) + R (b)
Let N-R (a) = s, N-R (b) = t, then S + T ＞ n, ax = 0 have s groups of linearly independent solutions, let A1 Let B 1 Because s + T is greater than N, so A1 ,as,b1,…… So A1 can be determined by A2 ,as,b1,…… B T is a linear expression
Party A and Party B both accept a task at the same time. In the four hours of working in the morning, party a spent 2.5 hours refitting the machine to improve efficiency. Therefore, Party A works in the morning
Party A and Party B both accept a task at the same time. In the four hours of morning work, party a spent 2.5 hours refitting the machine to improve efficiency. Therefore, at the end of morning work, Party A does 40 less than Party B; after the workers continue to work for four hours in the afternoon, Party A does 420 more parts than Party B in the whole day. How much do Party A and Party B do in this day?
Solving the first order equation with two variables
Let a do x per hour, then B do (1.5x + 40) / 4 per hour
(1.5+4)x=(1.5x+40)/4*(4+4)+420
5.5x=3x+500
2.5x=500
x=200
(1.5+4)x=5.5*200=1100
1100-420=680
A made 1100, B made 680
(5x-3)/4=3+(7x+5)/6
(5x-3)×3=12×3+2×(7x+5)
15x-9=36+14x+10
x=55
There are 480 kg grain in warehouse A and warehouse B. the grain in warehouse A is transported to warehouse B for 30 kg. The grain quantity in warehouse A is just three times that in warehouse B
How many kilos of original grain in two warehouses?
Give the formula
Warehouse a x warehouse b y
X+Y=480
(X-30)/(Y+30)=3
Y=480-X
(X-30)/(480-X+30)=3
X=390 Y=90
7x-3y = - 6 4x-5y = - 13 to solve the equation
If 7x-3y = - 6, 35x-15y = - 30 -------- (1) 4x-5y = - 13, 12x-15y = - 39 -------- (2) (1) -- (2), then: 23x = 9x = 9 / 23, substitute x = 9 / 23 into 7x-3y = - 6, then: - 63 / 29-3y = - 6y = 67 / 23, then: x = 9 / 23, y = 67 / 23
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