0,1X^2 + 0,4X - 14 = 0
X^2 + 4X - 140 = 0
D = 16 + 560 = 576 ; √ D = 24
x1 = ( - 4 + 24 ) : 2 = 10
X2 = ( - 4 - 24 ) : 2 = - 14
ОТВЕТ 10 и ( - 14 )
Ответ:
a) x₃=13 b) x₃=-1 d) x₃= -7/15
Объяснение:
xₐ=x₁+d(a-1)
x₂=x₁+d(a-1)
a) 8=3+d(2-1)
8=3+d
d=8-3=5 x₃=13
b)8=17+d(2-1)
d= -(17-8)= -9 x₃= -1
d) -1/3= -1/5+d(2-1)
d=1/5-1/3= -2/15 x₃= -7/15
-5x(x-2)+(x-3)(5x+1)= -5x²+10x+5x²+x-15x-3= 10x+x-15x-3= -4x-3.
3a(a-b)-(a+b)(3a-b)= 3a²-3ab-(3a²-ab+3ab-b²)= 3a²-3ab-(3a²+2ab-b²)= 3a²-3ab-3a²-2ab+b²= -3ab-2ab+b² = -5ab+b².
(2a-b)(3a+b)+(3a-5b)(a-b)= 6a²+2ab-3ab-b²+3a²-3ab-5ab+5b²= 9a²-9ab+4b².
(5x²y-y)(x-2y)-(x²+2y)(5x-3y)= 5x³y-10x²y²-xy+2y²-(5x³-3x²y+10xy-6y²)= 5x³y-10x²y²-xy+2y²-5x³+3x²y-10xy+6y²= 5x³y-10x²y²-11xy+8y²<span>-5x³+3x²y.
3a(a+3)+(2-a)(3a-4)= 3a</span>²+9a+6a+8+3a²+4a= 9a+6a-8+4a= 19a-8.
7x²(x-2y)-(x-y)(7x+y)=7x²-14xy-(7x²+xy-7xy-y²)= 7x²-14xy-(7x²-6xy-y²)= 7x²-14xy-7x²+6xy+y²= -14xy+6xy+y²= -8xy+y².
(3m-2n)(2m-3n)+(3n-m)(2n-m)= 6m²-9mn+4mn+6n²+6n²-3mn-2mn+m²= 7m²-18mn+12n².
(2a-5b²)(a+b)-(b²-2a)(a-5b)= 2a²+2ab-5ab²-5b³-(ab²-5b³-2a²+10ab)= <span>2a²+2ab-5ab²-5b³-ab</span>²+5b³+2a²-10ab= 4a²-8ab-6ab².