11 х 0,7 - 37 х 0,01 + 80 = 7,7-0,37+80=87,33
X^2+2x-5x-10-5x+x^2=0
2x^2+2x-5x-10-5x+x^2=0
2x^2-8x-10=0
x^2-4x-5=0
D=b^2-4ac=(-4)^2-4*(-5)=36
X1=(4-6):2=-1
X2=(4+6):2=5
1. A
2. D
3. B
(8x^2-4xy)/(y-2x)=(4x(2x-y))/(y-2x)=-(4x(y-2x))/(y-2x)=-4x
X² - 8x - 1 = 0
D = b² - 4ac
D = (-8)² - 4 × 1 × (-1) = 64 + 4 = 68
x₁,₂ = 8 ₊/₋√68 / 2