100 questions and answers of binary one time application questions

100 questions and answers of binary one time application questions

I'm sorry, I mean to give me the problem, not the equations. But it still works for me, thank you!

A binary one-time application problem
There are five big restaurants and two small restaurants in a university. After testing, one big restaurant and two small restaurants can be opened at the same time for 1680 students; if two big restaurants and one small restaurant can be opened at the same time for 2370 students
1. How many students can be served in a big restaurant and a small restaurant
2. If seven restaurants are open at the same time, can they serve 5300 students?

There is a big restaurant and a small restaurant for X and y students respectively,
According to the meaning of the question, we get the equations
X+2Y=1680
2X+Y=2370,
The solution is: x = 1020, y = 330,
(2) 5 × 1020 + 2 × 330 = 5760 > 5300, which can provide meals for the whole school

Let f (x) = 1 x ∈ [1,2]; f (x) = X-1 x ∈ (2,3] g (x) = f (x) - ax, X ∈ [1,3], where a ∈ R, note the maximum value of G (x)
Let f (x) = 1 x ∈ [1,2]; f (x) = X-1 x ∈ (2,3]
G (x) = f (x) - ax, X ∈ [1,3], where a ∈ R, the difference between the maximum and minimum of G (x) is h (a)
(1) Finding the analytic expression of function H (a)
(2) Draw an image of the function y = H (x) and point out the minimum value of H (x)
Don't copy. I can't understand the outside answer. I hope I can answer it manually! Continue to add

When x ∈ [1,2], G (x) = 1-ax
When x ∈ (2,3], G (x) = (1 -- a) X-1
The two-stage functions are monotone functions of first degree
If G (x) 1 increases, G (x) 2 increases, that is, a

How to solve the equation of 5 / 8 times 18 times x = 5
I know the answer is four out of nine

Five eighths times 18 times x = 5
x=5÷5/8÷18
x=8/18
x=4/9

cos5°/(sin50°+cos50°)=?
Sorry, wrong number, root 2cos5 ° / (sin50 ° + cos50 °) =?

cos5°/(sin50°+cos50°)
=cos5°/√2(√2/2sin50°+√2/2cos50°)
=1/√2*[cos5°/(sin50°cos45°+cos50°sin45°)]
=1/√2*cos5°/sin95°
=1/√2*1
=1/√2.
=√2/2

Given that the difference between the polynomial X & sup2; + ax-y + B and 6x & sup2; - 3x + 6y-3 is independent of the letter X, find the algebraic formula 3 (A & sup2; - 2ab-b & sup2;) - (4a & sup2;)
Find the algebraic formula 3 (A & sup2; - 2ab-b & sup2;) - (4a & sup2; + AB + B & sup2;)

It should be BX & sup2; (X & sup2; + ax-y + b) - (BX & sup2; - 3x + 6y-3) = x & sup2; + ax-y + b-bx & sup2; + 3x-6y + 3 = (1-B) x & sup2; + (a + 3) x-7y + B + 3, then the term coefficient of X is 0b = 1, a = - 3, so the original formula = 3A & sup2; - 6ab-3b & sup2; - 4A & sup2; - ab-b & sup2; = - A & sup2; - 7ab-4b & S

Granny Wang has 25 chickens and 15 ducks in her family. According to the formula 25 × 3 / 5 = 15, she compiles a multiplication problem and two division problems, and writes a step-by-step solution

Granny Wang has 25 chickens. The number of ducks is 3 / 5 of that of chickens. How many ducks are there?
Granny Wang's family has 15 ducks. The number of ducks is 3 / 5 of that of chickens. How many chickens are there?
Granny Wang has 25 chickens and Granny Wang has 15 ducks. How many parts of a chicken is a duck?

What is tan2 (a + b) equal to

tan2(A+B)=2tan(A+B)/[1-tan²(A+B)]

Quadratic function x ^ 2-5x + 4 = 0

x^2-5x+4
=x^2-x-4x+4
=x(x-1)-4(x-1)
=(x-4)*(x-1)
=0
So x = 4 or x = 1

Quickly, translate a (- 3,2) down three unit lengths to get point B. then the coordinates of the point B which is symmetric about the y-axis are? Why?
Answer in 15 minutes, urgent, please answer carefully!

Three units of downward translation of a is the ordinate minus 3 to get B (- 3, - 1). The point of symmetry of B about y axis is (3, - 1)