В)
5x² + 17x + 16 = 0
a =5, b = 17, c = 16
D= b² - 4ac
D= 17² - 4 * 5 * 16 = 289 - 120 = 169
-b +/- √D
X = _______
2a
-17 + √169 -17 + 13 -4 2
X₁ = _________ = _______ = ____ = ___
2 * 5 10 10 5
-17 - √169 -17 - 13 30
X₂ = _________ = ________ = ____ = 3
2 * 5 10 10
________________________________________________________
Г)
19x² - 23x + 5 = 0
a = 19, b = -23, c = 5
D = b² - 4ac
D = (-23)² - 4 * 19 * 5 = 529 - 380=149
-b +/- √D
X = _________
2a
- (-23) + √149 23 + √149
X₁ = ____________ = _________
2 * 19 38
- (-23) - √149 23 - √149
X₂= ____________ = _________
2 * 19 38
если что обращайся ))))
Привести подобные слагаемые-8ху + 8ху +4у-3у-4х+2х = у - 2 хподставить вместо х= 4.4 у= 10.310.3 - 2* 4.4 = 10.3 - 8.8 = 1.5
1)
(2t+4.3)(7t+8)=14t²+16t+30.1t+34.4=14t²+46.1t+34.4
2)
(-7-p)(m-4)=-7m+28-pm-4p
3)
(t+1)(t-7)-t²=t²-7t+t-7-t²=-6t-7
-6(-5)-7=30-7=23
4)
90z²+4=(5z+1)(18z+5)
90z²+4=90z²+25z+18z+5
4=25z+18z+5
4=43z+5
-43z=5-4
-43z=1
z=-(1/43)
5)
(0.1z+4s)(0.01z²-0.4zs+16s²)
0.001z³-0.16z²s+1.6zs²+0.04z²s-1.6zs²+64s³
0.001z³-0.12z²s+64s³
6)
(2u²+3)(3u-9)*u²=(6u³-18u²+9u-27)u²
6u^5-18u⁴+9u³-27u²
7)
(q-2)(7q+1)(4q-7)=(7q²+q-14q-2)(4q-7)
(7q²-13q-2)(4q-7)=28q³-49q²-52q²+91q-8q+14
28q³-101q²+83q+14
1) cos720+tg 30 ctg 210+sin 120 = сos2*360° + tg30°ctg(180° + 30°) +
+ sin(90° + 30)° = 1 + 1/√3*ctg30° + sin30° = 1 + (1/√3)*(√3) + 1/2 = 1 + 1 + 1/2 = 2(1/2)
tg0 °- 2ctg90° - sin0° - 3cos90° = 0 - 2*0 - 0 - 3*0 = 0
