А10=А1+9d=2+9*(-2)= 2-18=-16
4х^2+х-з=0
Д = 1+48=49
х= (-1+7) : 8 = 0,75 и х= (-1-8) 68=-1
Ответ : -1 ; 0,75
20x³y² + 4x²y = 4x²y(5x + 1)
9xyz² - 12xy²z = 3xyz( 3z - 4y)
20a⁴ - 5a³ + 15a⁵ = 5a³(4a - 1 + 3a²)
2x²y⁴ - 2x⁴y² + 6x³y³ = 2x²y²(y² - x² + 3xy)
5x-3+7x-4=8-15+11x
12x-11x= -7+3+4
x=0