If the square of the algebraic formula 2A + KAB + b-6ab + 9 does not contain AB term, the value of K is obtained

If the square of the algebraic formula 2A + KAB + b-6ab + 9 does not contain AB term, the value of K is obtained

The rule of polynomial combination is that only the terms with the same letter and exponent can be combined. Therefore, only the terms with ab can participate in the calculation. So here, only KAB and - 6ab are available. If the answer does not contain AB, the coefficient of these two terms can only be added to 0, so K-6 = 0, k = 6

Operation of mathematical polynomials
1. When a = - 1 / 9, B = 7, find the value of - (- A & sup2; + 2Ab + B & sup2;) + (- A & sup2; - AB + B & sup2;)
2. If the value of 4Y & sup2; - 2Y + 5 is 7, what is the value of 2Y & sup2; - y + 1?
Write down the steps of simplification

-(-a²+2ab+b²)+(-a²-ab+b²)
=a²-2ab-b²-a²-ab+b²
=-3ab
=-3*-1/9*7
=-7/3
4y²-2y＋5=7
That is 4Y & sup2; - 2y-2 = 0
That is, 2Y & sup2; - Y-1 = 0
That is, 2Y & sup2; - y = 1
So 2Y & sup2; - y + 1 = 2

How to use cross multiplication to factorize a quadratic trinomial whose quadratic coefficient is not one is best illustrated with examples!

For example, 2x + X-1 = 0 can be reduced to (2x-1) (x + 1) = 0