1) 14х2 - 5х - 1 = 0
D = 25 + 56 = 81 Кор.D = 9
x1 = 5 + 9/ 28 = 0,5
x2 = 5 - 9/ 28 = - 1/7
2) 2x2 + x + 67 = 0
D = 1 - 536 = - 535
Розв'язку немає
3) 2p2 + 7p - 30 = 0
D = 49 + 240 = 289 Kor.D = 17
p1 = -7 + 17/ 4 = 2,5
p2 = -7 - 17/ 4 = - 6
4) y2 - 3y - 5 = 0
D = 9 + 20 = 29 Kor.D = kor z 29
x = 3 + - kor z 29 / 2
5) 5x2 - 11x + 2 = 0
D= 121 - 40 = 81
kor D = 9
x1 = 11 + 9 / 10 = 2
x2 = 11 - 9 / 10 = 0,2
6) 9x2 - 30y + 25 = 0
D = 900 - 900 = 0
x = 30 / 18 = 5/3
Sinπ-sinπ/2+sin(π-π/3)-sinπ/3=sinπ-sinπ/2+sinπ/3-sinπ/3=-1
1)-32:8/3=12
2)12*0.26=3.12
3)3.12+15.6=18.72
<span>а) 24-x^2=0
x²=24
x=-2√6 U x=2√6
б) 81x^2=100</span>
x²=100/81
x=-10/9 U x=10/9
<span>(x+4)^2=3x+40
x²+8x+16-3x-40=0
x²+5x-24=0
x1+x2=-5 U x1*x2=-24
x1=-8 U x2=3
x^2+3x/2=x+7/4</span>
x²+3x/2-x-7/4=0
4x²+2x-7=0
D=4+112=116
x1=(-2-2√29)/8=-(1+√29)/4
x2=-(1-√29)/4
X^2+15x-2=0, то по теореме Виета
x1×x2=-2
x1+x2=-15
х1+х2+2х1×х2=-15+2×(-2)= -15-4=-19