Solve 1 math problem and solve 1 math problem

a={x|0,-4｝

If a intersects b=b, b={x|0, -4} or b={x|0} or b={x|-4｝

b={x|0}, a -1 = 0, a = 1

b={x|-4}, 16-8(a+1)+a-1=0, a-8a+7=0, a=1 or 7;

b={x|0,-4}, a=1

If a and b = b, b at least = {x|0,-4｝

So a=1

a=={0，-4｝

The first question: a crosses b=b

When x=0 is brought in, a -1=0 is given, so a = 1

Bring in a=1 separately: when a=1 gets x +2x=0 gets x=0 or x=-2 doesn't meet the proposal to round.

When a=-1 gives x =0 and gets x=0, it fits the question, so a=-1

When x=-4, 16-8(a+1)x+a-1=0 is solved to a= 1 or a=7

When a=1, it is not rounded.

When a=7, x +16x+48=0 is solved to be x=-4 or x=-12 and rounded off.

So a=1

The second question is the process of the boundary of the first question, and when a=1 is x=0 x=-4 are the solutions of the equations.

So a=1

1) From the condition, it can be calculated that a={0,-4}

a b=bb is a subset of a.

b may be an empty set, {0}{-4}{0,-4}

When b is an empty set.

2（a+1））²4（a²-1）<0

Solution: a<-1

When b = {0}

a=-1 when b={-4}

No solution. When b={0,-4}

a=1 in summary.

a<=-1 or a=1

2) a b = b and b is the solution of a quadratic equation.

b=｛0，-4｝

Solution: a<-1

a=(-4,0).

If a b = b, then b = (2, 4....

Bring in 2 to get a=-1 or -3Substituting 4 to get a is unsolvable. So a=-1 or -3

If a b = b, then b can be an empty set, and the above. I'll figure it out for myself.

(1÷2)×(1÷2)×

The cylindrical volume is the volume of the cube.

times (think of the cube side length as 1) 4 =

The cylindrical volume is.

Cubic centimetre.

Hello, according to the sinusoidal theorem, a2+b2=2c2

cosc=（a^2+b^2-c^2)/2ab=(a^2+b^2)/4ab>=1/2

So c belongs to (0, 3], if in doubt, you can raise it, we are all **.

Solution: Let a= (1-x) and b= (x

3)(a,b≥0)

Therefore there is: a 2

b^2=1-x

x3=4(a,b≥0)

This is to establish a plane with a as the transverse axis and b as the vertical axis, with the origin as the center of the circle, and 2 as the radius within the first quadrant of 1 4 arcs.

The drawing shows that the objective function a is set

b=k, which is a parallel straight line bundle with a slope of -1.

When it intersects the arc in the first quadrant, the intercept range of the line on the y-axis is the range of k, i.e., a

b. The diagram depicts the critical case:

1.When tangent: d=|k|2=2(k>0), and k=2 2 (i.e., kmax=f(x)max=m=2 2).

2.When intersecting the two ends of the arc: k=2 (i.e., kmin=f(x)min=m=2).

Therefore, there is: m m = 2 2 2 = 2 2

Before the destruction of the army in four years, if there was Xiao Ming, then the age of the whole family should be 16 years younger than this year's age and 69-54=15, so Xiao Ming is only 3 years old this year: 4-(16-15)=3.

Sister this year: 3+2=5 years old;

The age of Mom and Dad is 69-3-5=61 years old, and the age of Mom is: (61-1) 2=30 years old;

Dad's age is: 30 + 1 = 31 years old.

The total age difference of the four people who existed four years ago should be 16, but the actual difference is now 15, and one person was born three years ago.

Xiao Ming (the youngest) is only 3 years old this year: 4-(16-15)=3.

Sister this year: 3+2=5 years old;

The age of Mom and Dad is: 69-3-5 = 61 years old, and the age of Mom is: (61-1) 2 = 30 years old;

Dad's age is: 30 + 1 = 31 years old.

There were 31 days in August, and 56 were built in the first eight days, so 7 units were built in one day, 31 times 7,217 units.

Want an equation?

At this rate, x units can be produced by the end of the month.

x/31=56/8

x=217A; At this rate, 217 units will be produced by the end of the month.

If you have any questions, please feel free to ask.

Set up the first day to produce x units. x*8=56

So 7 units were produced on the first day. One month (31 days in August) produces 7 * 31 = 217 units.

At this rate, x units can be produced by the end of the month.

56/8=x/31

x=217

Solution: A play on words, 27 + 2 = 29 has no practical meaning.

The three of them actually only paid 27 yuan, 25 yuan for accommodation, and 2 yuan was greedy by the waiter.

Can't add that because there's 25 bucks in the boss**.

The waiter's 2 yuan is 27 yuan.

"3 x 9 = $27 + $2 from the waiter = $29"This step is wrong, because the 27 yuan already includes the 2 yuan that the waiter secretly hid, and the remaining 3 yuan after the waiter secretly hid 2 yuan.

It shouldn't be 27+2=29; Rather, it should be 27-2=25;

Because the three of them ended up paying a total of 27 yuan, instead of 30 yuan, 25 yuan of the 27 yuan was in the boss's place, and 2 yuan was in the waiter's place.

The algorithm is wrong (each person only spent more than 8 yuan [25 3] to the boss. Plus the waiter's 2 yuan, each person is exactly 9 yuan)

It was discounted.

China generally uses the Richter scale. Usually the ** less than the level is called small**, the ** level ** is called sensible**, and the ** larger than the level ** is called destructive**. For every 1 magnitude difference, the energy released by ** differs by a factor of about 30.

For example, a magnitude 7** is equivalent to 30 magnitude 6**, or equivalent to 900 magnitude 5**, and the magnitude difference is that the energy released is evenly doubled.

Therefore, the maximum amplitude of the grade ** is 398 times the maximum amplitude of the grade 5**.

Note: The difference between dividing and dividing by.

15 4 and 13 20

What grade are you? The above question uses the knowledge of the differentiation small and the reciprocal of multiplication.

If you are a student in the fifth grade or lower, see below for this question.

Keep the appropriate decimal as needed).