If the equation 9 ^ x + (4 + a) * 3 ^ x + 4 = 0 about X has real roots, find the value range of A Using the method of separating variables Don't think of it as a quadratic equation with one variable of 3 ^ X. I'll do that. I'll separate variables

If the equation 9 ^ x + (4 + a) * 3 ^ x + 4 = 0 about X has real roots, find the value range of A Using the method of separating variables Don't think of it as a quadratic equation with one variable of 3 ^ X. I'll do that. I'll separate variables

a=(-9^x-4)/3^x-4=-3^x-4/3^x-4
3 ^ x + 4 / 3 ^ x > = 2 radical 4 = 4
a

Does the equation x ^ 2-6x + 9 = 3 have a real root? Why?

x²-6x+9=3
x²-6x+6=0
Δ=36-24=12＞0
So the equation has two real roots
If you don't understand, please hi me, I wish you a happy study!

The set of all real roots of equation x2-9 = 0 is______ ．

From x2-9 = 0, we can get x = 3 or x = - 3. That is to say, the set of all real roots of equation x2-9 = 0 is {3, - 3}, so the answer is: {3, - 3}

Parabola is the image of quadratic function y = ax squared - 3x + A, then the value of a is?
emergency

Since it is a parabola, the opening must be downward, needless to say, the derivation of the original formula shows that y '= 2ax-3 2a is the acceleration of gravity g, and the slope of the parabola is 2a, that is, 2A = GA = g / 2

38. Xiaoming's telephone number is a seven digit ABCDEF. Cut it off and divide it into a three digit ABC and a four digit defg, or a four digit ABCD and a three digit EFG. However, the sum of the first three digits and the last four digits, or the sum of the first four digits and the last three digits, are two equal four digits, Xiao Liang asked the uncle of the telecommunication bureau to give him a number with the characteristics of Xiaoming's telephone number, and the seven digit number is bigger than Xiaoming's. The uncle of the telecommunication bureau said that the number of Xiaoming's is the largest. Then the telephone number of Xiaoming's is & # 160; &# 160; &# 160; &# 160; &# 160; &# 160; &# 160; &# 160; &# 160
 
35. There are several apples and pears in each bag. If 5 apples and 3 pears are packed in one bag, and there are 4 more apples, the pears are just finished; if 7 apples and 36 pears are packed in one bag, and there are 12 more pears, the apples and pears are shared__________ only
 

38. Xiaoming's telephone number is a seven digit ABCDEF. Cut it off and divide it into a three digit ABC and a four digit defg, or a four digit ABCD and a three digit EFG. However, the sum of the first three digits and the last four digits, or the sum of the first four digits and the last three digits, are two equal four digits, Xiao Liang asked the uncle of the telecommunication bureau to give him a number with the characteristics of Xiaoming's telephone number, and the seven digit number is even larger than Xiaoming's. The uncle of the telecommunication bureau said that this number is the largest in Xiaoming's family. Then the telephone number of Xiaoming's family is 9999000
35. There are several apples and pears in each bag. If 5 apples and 3 pears are packed in one bag, and there are 4 more apples, the pears are just finished; if 7 apples and 36 pears are packed in one bag, and there are 12 more pears, the apples and pears are shared____ one hundred and thirty-two
______ only

If | x-2y | + | 5x-7y-2 |, x = y=

(guarantee right)
x-2y=0
5x-7y-2=0
x-2y=0
5x-7y=2
5x-10y=0
5x-7y-5x+10y=2
3y=2
y=2/3
x=4/3
171819sss answer for you at any time
If you are satisfied, please [click satisfaction answer] (potato group)

Solution ratio: 3:0.625 of 16 = x: 50 42:18 = x: 17 45 = 0.09 0.21.96: x = 16:55
three-sixteenths

X=37.5
X = 39 and two thirds
X=100
X=6.7375

The calculation method of the cofactor of the fourth order determinant algebra,
Fourth order determinant
-1 0 5 0
1 7 4 0
2 4 10 6
3 - 1 x 1 find the value of the algebraic covalent of X, I just learned, hope to be more detailed

A34 = (-1)^(4+3) M34 = (-1)*
-1 0 0
1 7 0
2 4 6
= - (-1)*7*6
= 42

Use a simple algorithm: 3 / 4 times 1 / 9 plus 1 / 4 divided by 9

What is the limit for the absolute value of SiNx divided by X to approach zero

Let f (x) = SiNx / | X|
Then LIM (x → 0 +) f (x)
=lim(x→0+)sinx/x
=1
lim(x→0-)f(x)
=lim(x→0-)sinx/(-x)
=-1
The left and right limits are not equal
So there is no limit