Ответ:
232а
3x^2+15x-7=0
D = 15^2 - 4*3*(-7) = 309
x1 = (-15-√309)/(2*3) = -2.5 - √309 / 6 ≈ -5.4
x2 = (-15+√309)/(2*3) = -2.5 + √309 / 6 ≈ 0.4
232б
-2x^2-11x+3=0
2x^2+11x-3=0
D=11^2-4*2*(-3)=145
x1 = (-11-√145)/(2*2) = (-11-√145) / 4 ≈ -5.8
x2 = (-11+√145)/(2*2) = (-11+√145) / 4 ≈ 0.3
233
x^2 - 1000x + 89199 = 0
D = 1000^2 - 4*89199 = 643204 = 802^2
x наим = (1000 - √643204) / 2 = (1000 - 802) / 2 = 99
1) 5х+у=7|×4
7х-4у=-1
20х+4у=28
7х-4у=-1
27х=27
х=27/27
х=1
у=7-5х
у=7-5×1=7-5
у=2
2) 6х-5у=23
2х-7у=13|×3
6х-5у=23
6х-7у=39
2у=-16
у=-16/2
у=-8
6х-5×(-8)=23
6х+40=23
6х=23-40
6х=-17
х=-17/6
3) 5х-2у=16|×3
8х+3у=38|×2
15х-6у=48
16х+6у=76
31х=124
х=124/31
х=4
5×4-2у=16
-2у=16-20=-4
у=(-4)/(-2)
у=2
4) 5х-4у=10|×3
2х-3у=-3|×4
15х-12у=30
8х-12у=-12
7х=42
х=42/7
х=6
5×6-4у=10
-4у=10-30
-4у=-20
у=(-20)/(-4)
у=5
5) 4а+6b=9|×3
3a-5b=2|×4
12a+18b=27
12a-20b=8
38b=19
b=19/38
b=1/2=0,5
4a+6×0,5=9
4a=9-3
4a=6
a=6/4
a=1,5
6) 9m-13n=22|×2
2m+3n=-1|×9
18m-26n=44
18m+27n=-9
-53n=53
n=53/(-53)
n=-1
9m-13×(-1)=22
9m=22-13
9m=9
m=9/9
m=1
(6a^2+5x)^2=36a^10+60a^5+25x^2
(10m^5+6m^2n^3)^2=100m^10+120m^7n^3+36m^4n^6