If y + 3 = √ 2x-5 + √ 10-4x, then the value of 2XY is ()

If y + 3 = √ 2x-5 + √ 10-4x, then the value of 2XY is ()

y+3=√2x-5+√10-4x=√(2x-5)+√2(5-2x)
Because the formula under the root sign is ≥ 0
So there are
2x-5≥0
2(5-2x)≥0
So 2x-5 = 0
That is, x = 5 / 2
y=√2x-5+√10-4x-3=0+0-3=-3
So 2XY = 2 × 5 / 2 × (- 3) = - 15

It is known that the value of X / 1 + Y / 1 = 5, x-2xy-y / 2x + 5xy-2y is

Original formula = 2 + 7xy / (x-2xy-y)
The numerator and denominator of the following formula are reciprocal
(x-2xy-y)/7xy=1/7y-2/7-1/7x
Your condition should be
1 out of X-1 out of y = 5 or you can't do it
(x-2xy-y)/7xy=1/7y-2/7-1/7x=-2/7-5/7=-1
-The reciprocal of 1 is still - 1, so 7xy / (x-2xy-y) = - 1
Original formula = 2-1 = 1
You should give some points for typing so many words

Given y = 2x - 5 + 5 - 2x - 3, find the value of 2XY

The solution is: x = 52, then y = - 3. Substituting x = 52, y = - 3 into 2XY, we get: 2 × 52 × (- 3) = - 15

A drink shop sells a juice, which is 1 yuan more expensive than B juice. Xiao Ming and his four friends asked for two glasses of a juice and three glasses of B juice, which cost 17 yuan in total
Clear. Ensure correct

Let a = X
B = y
X-Y=1
2X+3Y=17
solution
x=1+y
2(1+y)+3y=17
2+2y+3y=17
5y=15
y=3
x=1+y
x=4
Answer a juice = 4 yuan, B juice = 3 yuan

First of all, in the evaluation of the square of the cube-2a of a + the square of 2A / a-2a, where a = - 1

Cube of a - 2A squared + 2A / 2A squared - 2A
=2a(a-1)/a(a²-2a+1)
=2a(a-1)/a(a-1)²
=2/(a-1)
When a = - 1
The original formula is 2 / (A-1) = 2 / (- 1-1) = - 1

A passenger car starts from place a to place B at the speed of 30 km / h. after 45 minutes, a freight car starts from place B to place a at the speed of 10 km faster than the passenger car per hour. If the two cars just meet at the midpoint of Party A and Party B, calculate the distance between Party A and Party B

Solution: suppose the freight car meets the passenger car in X hours, then there is: 30 × 4560 + 30x = (30 + 10) x, the solution is: x = 94. S = 94 × 40 × 2 = 180 km. Answer: the distance between a and B is 180 km

When x + y = 1, x + 3Y = 3, the value of the algebraic formula x ^ 2 + 4xy + 3Y ^ 2 is

Original formula = (x + y) (x + 3Y)
=1×3
=3

The speed of car a is 50 km / h, and that of car B is 40 km / h. when car a drives over 13-50 km from a and B, it meets with car B______ Kilometers

A: the distance between a and B is 225 km, so the answer is: 225

6x+12.5-2x=22.5

6x+12.5-2x=22.5
4x=22.5-12.5
4x=10
x=2.5
Hope to help you_ ∩)O

Car a and car B start from two places 560 kilometers apart and travel in opposite directions. It is known that the speed ratio of car a and car B is 4:3. After 4 hours, the two cars meet. How many kilometers does car a travel per hour?

560 △ 4 × 44 + 3, = 140 × 47, = 80 km / h; answer: car a travels 80 km / h