When Wang Ming subtracted the difference of 2B + B-5 from a polynomial, he forgot to enclose the two polynomials in brackets When Wang Ming subtracts the difference of 2B + B-5 from a polynomial, he forgets to enclose the two polynomials in brackets. Therefore, the two terms after the subtraction do not change sign. The result is that the difference is the square of B + 3b-1? And work out the right answer

b²＋3b-1＋2b－b＋5=b²＋4b＋4

When Wang Ming calculated the difference of a polynomial minus 2B ^ 2 + B-5, he forgot to enclose the two polynomials in brackets for a moment, so the two terms after the subtraction did not change sign, and the result was B ^ 2 + 3b-1. Based on this, he calculated the binomial and calculated the result

If a ^ 2 + B ^ 2 = 2, then the value of formula (a ^ 2-2ab-3b ^ 2) - (3a ^ 2-2ab-b ^ 20) is

(3a ^ 2-2ab-b ^ 20) B ^ 20 here should be B & # 178;
a²+b²=2
(a²-2ab-3b²)-(3a²-2ab-b²)=a²-2ab-3b²-3a²+2ab+b²=-2a²-2b²
=-2(a²+b²)=-2×2=-4

Remove brackets to evaluate 5ab - [2 (2a square - ab-b Square) - 3 (a square + b square)] - 3 (ab-2b Square)

5ab-[2(2a²-ab-b²)-3(a²+b²)]-3(ab-2b²)
=5ab-(4a²-2ab-2b²-3a²-3b²)-3ab+6b²
=5ab-4a²+2ab+2b²+3a²+3b²-3ab+6b²
=(5ab+2ab-3ab)+(-4a²+3a²)+(2b²+3b²+6b²)
=4ab-a²+11b²

It is known that in the positive proportion function y = (a + 3) x, the value of Y increases with the increase of X, while in the positive proportion function y = (2a + 2) x, the value of Y decreases with the increase of X, and a is an integer,
Find the analytic expressions of these two functions

In the positive scale function y = (a + 3) x, the value of Y increases with the increase of X
a+3>0
a>-3
In the proportional example y = (2a + 2) x, the value of Y decreases with the increase of X
2a+2

If the function y = (2a + 5) x & sup2; + (1-3a) x (a is a constant) is a positive proportional function, then the value of a is

The quadratic term is zero, so a = - 2.5

Solving inequality 2x ^ 2 + (5 + 2a) x + 5A

2x^2+(5+2a)x+5a
=(x+1)(2x+5a)

If the solution set of inequality x ^ 2-x-2 > 0 is a, inequality 2x ^ 2 + (5 + 2a) + 5A

A: (negative infinity, - 1) U (2, infinity) B: x = - 2.5, x = - A if - 2.5 > - a > 2.5 if - 2.51 and A1

The value range is known u ∈ R, a = {X / - 1 ≤ x ≤ 3}, B = {X / x-a ＞ 0}. 1. A is included in B, and the value range of real number a is obtained. 2. A ∩ B ≠ empty set

A={x|-1≤x≤3}
B={x|x-a＞0}={x|x＞a}
(1) A is contained in B
Then a ＜ - 1 (not equal to - 1)
(2) A ∩ B ≠ empty set
Then a < 3 (cannot be equal to 3, otherwise the intersection is empty)
If you don't understand, please hi me, I wish you a happy study!

Try to explain that the product of four consecutive integers plus 1 is a complete square number

Proof: let four continuous integers be a, a + 1, a + 2, a + 3, a (a + 1) (a + 2) (a + 3) + 1 = (a + 3a) (a + 3A + 2) + 1 = (a + 3a) + 2 (a + 3a) + 1 = (a + 3A + 1)