Question

срочно
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Answer 1

Решение:

1. a) (а+5)^2 = а^2 + 10a + 25

б) (3y-x)^2 = (3y)^2 - 2*3yx + x^2 = 9y^2-6yx + x^2

в) (2b-1)(2b+1) = (2b)^2-1^2 = 4b^2 - 1

г) (4a+3b)(4a-3b) = (4a)^2 - (3b)^2 = 16a^2 - 9b^2

2. (a-3)^2 - 3a(a-2) = - 2a^2 + 9

3. a) (x-3)^2 - x(x+2,7) = 9

x^2-6x+9-x^2-2,7x = 9

- 8,7x = 0

x = 0

б) (3y-5)*(3y+5) = 0

3y-5 = 0 ➞ x1=5/3

3y+5 = 0 ➞ x2=-5/3