2/5(x-2)=2(x-3)-6
2/5x-4/5=2x-6-6
2x-2/5x= -6-6+4/5
1 3/5x= -11 1/5
x= -7
(9x⁴ - 16y³)² = (9x⁴)² - 2 * 9x⁴ * 16y³ + (16y³)² = 81x⁸ - 288x⁴y³ + 256y⁶
Х^2 + y^2 = 25
X - y = 7
X = y + 7
( y + 7 )^2 + y^2 = 25
y^2 + 14y + 49 + y^2 = 25
2y^2 + 14y + 24 = 0
D = 196 - 192 = 4 = 2^2
y1 = ( - 14 + 2 ) : 4 = - 3
y2 = ( - 14 - 2 ) : 4 = - 4
X1 = - 3 + 7 = 4
X2 = - 4 + 7 = 3
Ответ ( 4 ; - 3 ) ; ( 3 ; - 4 )
1) 1 - sin²α = cos²α
2) (1 + sinα)(1 - sinα) = 1 - sin²α = cos²α