Question

упростите выражение :

1) (11а - b) ² + (9a + 7b)(8a - 13b)

2) (18x + 5y)(2x - 4y) - (6x - 3y)²

3) 4x(3x - 2y) - (10y - 0,4x)²

4) (15a + 2b)² - (3a - 7b)(3b - 5a)

Answer 1

1)

$121 {a}^{2} - 22ab + {b}^{2} + 72 {a}^{2} - 117ab + 56ab - 91 {b}^{2} =193 {a}^{2} - 90 {b}^{2} - 83$

2)

$36 {x}^{2} - 72xy + 10xy - 20 {y}^{2} - 36 {x}^{2} + 36xy - 9 {y}^{2} = - 29 {y}^{2} - 26xy$

3)

$12 {x}^{2} - 8xy - 100 {y}^{2} + 8xy - 0.16 {x}^{2} = 11.84 {x}^{2} - 100 {y}^{2}$

4)

$225 {a}^{2} + 120ab - 9ab + 15 {a}^{2} + 21 {b}^{2} + 15 {a}^{2} = 255 {a}^{2} + 21{b}^{2} + 111ab$