Knowledge network of Biology Unit 5 in Volume 2 of Grade 7

Knowledge network of Biology Unit 5 in Volume 2 of Grade 7

Integral operation problems in Volume 2 of Grade 7
Good, good

1、 Calculate (x-3) (X-7) + 42123 - 124 * 122 (2a + B + 3) (2a + B-3) (x + 2y-1) (x-2y + 1) - (x-2y-1). (a ^ 2 + 3) (A-2) - A (a ^ 2-2a-2) (2). (3 / 4A ^ 6x ^ 2 + 6 / 5A ^ 3x ^ 4-0.9ax ^ 3) △ 3 / 5AX ^ 2 1) ^ 25A ^ 2B - [3AB ^ 2 - (4AB ^ 2-2a ^ 2b)] (- 3a-2) (3a-2) (3 + 2a) (...)

(123+122)*(123-122)
(123+122)*(-123-122)

Square of 123 - square of 122
-The complete square of (123 + 122)

The operation of mathematical integral,
（1）2a^4b-(-a^2b)^3÷[3(-1/2ab)^2]
（2）(2x+y)^2(2x-y)^2-(4x^2+y^2)^2

Direct reduction: A ^ 4B (2 + 4A ^ 4B ^ 4 / 3)
（-2x+y)^2(2x-y)^2-(4x^2+y^2)^2
=（4x^2-y^2）^2-(4x^2+y^2)^2
=(4x^2-y^2+4x^2+y^2)(4x^2-y^2-4x^2-y^2)
=16x^2y^2