[1;2] ∫ 4x^3 dx = x^4 |[1;2] = (2^4 - 1^4) = 16-1 = 15
9x^2+6xy+y^2-z^2=(9x^2+6xy+y^2)-z^2=(3x+y)^2-z^2=(3x+y-z)(3x+y+z)
Упростим выражение:
-0.74b +0.78b -0.23b +1.4b = 2,18b - 0,97b = 1.21b
a) при а=-3
1,21 *(-3) = -3,63
б) при b= 6 2/3
1,21 * 6 2/3 = 121/100 * 20/3 = (121*20)/(100*3)=
= (121*2) /(10*3) = (121*1)/ (5*3) = 121/15= 8 1/15
4x²+20x+1=0 D=400-16=384 √D=√384 384=4*96=16*2*2*6
√D=8√6
x1=1/8[-20-8√6]≈-4.9
x2=1/8[-20+8√6]≈-0.05