If angle 1 plus angle 2 equals angle 2 plus angle 3, and angle 1 equals 55 degrees, then how many degrees does angle 3 equal

If angle 1 plus angle 2 equals angle 2 plus angle 3, and angle 1 equals 55 degrees, then how many degrees does angle 3 equal

∵∠1＋∠2＝∠2＋∠3
∴∠1＝∠3
∵∠1＝55°
∴∠3＝∠1＝55°

A triangle angle one equals 35 degrees, angle two equals 55 degrees, then how many degrees does angle three equal?

180-35-55=90

Calculation: (1 + 0.23 + 0.34) * (0.2903 + 0.34 + 0.56) - (1 + 0.23 + 0.34 + 0.56) * (0.23 + 0.34)

Let 0.23 + 0.34 + 0.56 = a
Then 1 + 0.23 + 0.34 = 1 + a-0.56
0.23+0.34+0.56=a
1+0.23+0.34+0.56=1+a
0.23+0.34=a-0.56
So the original formula = a (1 + a-0.56) - (1 + a) (a-0.56)
=a*1+a(a-0.56)-1*(a-0.56)-a(a-0.56)
=a-(a-0.56)
=a-a+0.56
=0.56

Let f (x) be a function defined on the set of real numbers R, and f (- x) = f (x), f (x) be an increasing function on the interval (- ∞, 0), and f (2a & sup2; + A + 1) < f (3a & sup2; - 2A + 1), then find the value range of real number a

Observation shows that:
2A & sup2; + A + 1, 3A & sup2; - 2A + 1 are all greater than 0
Because △ 3A & sup2; - 2A + 1
a²-3a

What is the quotient of the sum of the largest one digit and its reciprocal divided by eight ninths?

（9-1/9）÷8/9
=80/9÷8/9
=10

(4m + 1) (4m-1) - 3M times (3m-2)

(4m + 1) (4m-1) - 3M by (3m-2)
=16m²-1-9m²+6m
=7m²+6m-1

12. Let a = [6 * 8-2], B = 6 * 8-2, C = "6 * 8-2", the legal expression is () A.A + B.B + c.a-c d.c-b
Last year's computer level 2 VF real problem. How to do this problem? Please explain more popular, thank you!

Choose a, a + B, because C is a string!

(x-5)/(x/7)+(x-2)/(x-4)=(x-3)/(x-5)+(x-4)/(x-6)

(x-5)/(x-7)+(x-2)/(x-4)=(x-3)/(x-5)+(x-4)/(x-6)
(x-7+2)/(x-7)+(x-4+2)/(x-4)=(x-5+2)/(x-5)+(x-6+2)/(x-6)
1-2/(x-7)+1-2/(x-4)=1-2/(x-5)+1-2/(x-6)
2/(x-7)+2/(x-4)=2/(x-5)+2/(x-6)
1/(x-7)+1/(x-4)=1/(x-5)+1/(x-6)
(x-4+x-7)/(x-4)(x-7)=(x-6+x-5)/(x-5)(x-6)
(2x-11)/(x^2-11+28)=(2x-11)/(x^2-11+30)
Because x ^ 2-11 + 28 is not equal to x ^ 2-11 + 30
The denominator is not equal. If the equation holds, the numerator can only be 0
2x-11=0
x=11/2
It is proved that x = 11 / 2 is the solution of the original equation

If you subtract three-quarters from a number and three-quarters from it, one and two-thirds of the difference is five sixths
Specific process and answers

Five sixths divided by one and two thirds plus three fourths plus three fourths equals two

A problem of invertible matrix
If the real matrix A of order n satisfies a ^ 11 = 0 and E is the identity matrix of order n, then
A + e reversible, A-E irreversible
B is irreversible
C is reversible
D A + e is irreversible, A-E is reversible

A ^ 11 = 0, e is the n-order identity matrix, a ^ 11 + e = e, that is (a + e) (a ^ 10-A ^ 9 + A ^ 8-A ^ 7 +... - A + e) = e. from the definition of invertible matrix, we know that a + e is invertible. Similarly, a ^ 11-e = - E, that is (A-E) (a ^ 10 + A ^ 9 + A ^ 8 +... + A + e) = - E (A-E) (- A ^ 10-A ^ 9-A ^ 8 +... - A-E) = E