How to do these two questions?

Question 1. Count from the back to the front. 33 + 27 3 14 6 = 36 years old.

Question 2. The three loaves are denoted as a, b, and c. The front and back are marked as a1, a2, b1, b2, c1, c2 respectively.

Divide into three parts.

First A1 and B1

Second A2 and C1

3rd B2 and C2

Exactly 15 minutes.

If you are satisfied, hope.

If you don't understand, you can ask.

Good luck with your studies! o(∩_o~

36 (years old) 2, put the first cake and the second cake into the pot, 5 minutes, turn the first cake over, take out the second one, put in the third cake, 5 minutes later, the first cake has been baked and taken out, at this time, the second and third are only one side, put it in the pot, and the second side is baked for 5 minutes, so that a total of 15 minutes, 3 cakes are baked.

For the first 5 minutes, sear the front of 1 loaf and the front of 2 loaves;

For the second 5 minutes, bake the reverse side of 1 loaf and the front of 3 loaves;

For the third 5 minutes, bake 2 loaves on the reverse side and 3 loaves on the reverse side.

15 minutes 3 loaves are fine.

Let the father's age be x, (x 6+14)*3-27=.

ABC three cakes, first A positive B positive, then A anti-C positive, and finally B anti-C anti. 15min is enough.

There is no idea in the first question, try to see what happens.

So we found him in the loop at 3674Since 98 4, the remainder is 2

So the result is the second number of this cycleThe same goes for the second question.

So we found that after the first change, we changed it three times to return to 8762020 3, and the remainder was 1

So he is equivalent to 876 and changes again, getting 687,Therefore, Xiao Ming has 6 balls in his hand.

1).Find differential equations.

dy dx=(y x)+(y x).

Solution: Let y x=u, then y=ux; dy/dx=u+x(du/dx)；

Substituting the original form and simplifying it yields: x(du dx)=u ; Separate the variables to obtain: du u = (1 x)dx;

Integral: -1 U=LN x +LNC=LN(C X);

Therefore u=-1 [ln(c x); Substituting u=y x into the solution is obtained: y=-x [ln(c x);

2) .Find the differential equation y'+y=xe (-x) satisfies the initial condition y(0)=4;

Solution: Find the homogeneous equation first.

y'+y=0: Separate the variables to get dy y=-dx;

Points: lny=-x+lnc ; Therefore y=c e (-x);

Replace c with x to get the function u: y=ue (-x).

Take the derivative to get dy, dx=y'=-ue^(-x)+[e^(-x)](du/dx)..

Substituting "-ue (-x)+[e (-x)](du dx)+ue (-x)=xe (-x).

Simplified: du dx=x, so u= xdx=(1 2)x +c;

Substituting the u value into the equation gives the solution: y=[(1 2)x +c]e (-x).

Substituting the initial condition y(0)=4 gives c=4;Therefore, the special solution that satisfies the initial condition is: y=[(1 2)x +4]e (-x);

(1) Solution: Original formula = 4-3-5 2

2) Solution: Original formula = 2 2+1- 2+1

I hope it helps!

Question 1: The root number 16 is equal to 4, and the cubic of 27 is equal to -3

1+9 16 is equal to 25 16, the root number is special 25 16 is equal to 5 4, and the final result is 4+(genus -3)-5 4 is equal to -1 4

Just do it with your normal heart.

The first one is 1 and the second one is 0

To be continued.

4. Mainly use the rule of Lopida.

Note the composite function derivative.

For reference, please smile.

Yuan. 2.The remaining 60% is 20% more than the 40% used, then this extra 20% is 10 kg, then the total weight = 50 kg.

The first time, if it is balanced, it means that the mass on both sides is equal, and the one with insufficient quality is not measured in the four bags with 2 bags at each end of the scale, and the 2 bags of apples at the higher end (the light weight) are placed at each end of the scale, and the bag at the higher end is the one with less mass.

For the first time, if you say flat light weight apples on the scale, take the higher end (light weight) of the 4 bags of apples, each put 2 bags on both ends of the scale, and the same goes for the following.

So the most 3 times can be guaranteed to find the apple.