№1
![\frac{4x-5}{3x-1}=7, \frac{4x-5}{3x-1}=7,](https://tex.z-dn.net/?f=%5Cfrac%7B4x-5%7D%7B3x-1%7D%3D7%2C)
3x-1≠0, x≠1/3
4x-5=7(3x-1),
17x=2,
x=2/17
№2
3xy-2+3x-2y=3x(y+1)-2(y+1)=(y+1)(3x-2)
№3
![\frac{6^2-0,176^2}{6,176}=\frac{(6-0,176)(6+0,176)}{6,176}=\frac{5,824\cdot6,176}{6,176}=5,824 \frac{6^2-0,176^2}{6,176}=\frac{(6-0,176)(6+0,176)}{6,176}=\frac{5,824\cdot6,176}{6,176}=5,824](https://tex.z-dn.net/?f=%5Cfrac%7B6%5E2-0%2C176%5E2%7D%7B6%2C176%7D%3D%5Cfrac%7B%286-0%2C176%29%286%2B0%2C176%29%7D%7B6%2C176%7D%3D%5Cfrac%7B5%2C824%5Ccdot6%2C176%7D%7B6%2C176%7D%3D5%2C824)
№4
x/4+(4+x)/2≥(3x+8)/8-3/2,
2x+4(4+x)≥3x+8-12,
3x≥-20,
x≥-6 2/3
№5
2x+4y=-4,
3y-2x=8;
7y=4,
y=4/7,
2x+16/7=-4,
14x=-20,
x=-10/7,
x=-1 3/7
№6
a/(a-0.75a)=a/(0.25a)=4
№7
![\frac{\sqrt{15.3}\sqrt{3.4}}{\sqrt{0.18}}=\sqrt{\frac{0.1\cdot9\cdot17\cdot0.1\cdot2\cdot17}{0.01\cdot2\cdot9}}=\sqrt{17^2}=17 \frac{\sqrt{15.3}\sqrt{3.4}}{\sqrt{0.18}}=\sqrt{\frac{0.1\cdot9\cdot17\cdot0.1\cdot2\cdot17}{0.01\cdot2\cdot9}}=\sqrt{17^2}=17](https://tex.z-dn.net/?f=%5Cfrac%7B%5Csqrt%7B15.3%7D%5Csqrt%7B3.4%7D%7D%7B%5Csqrt%7B0.18%7D%7D%3D%5Csqrt%7B%5Cfrac%7B0.1%5Ccdot9%5Ccdot17%5Ccdot0.1%5Ccdot2%5Ccdot17%7D%7B0.01%5Ccdot2%5Ccdot9%7D%7D%3D%5Csqrt%7B17%5E2%7D%3D17)
№8
a2=a1+d=5, d=30,
a1=a2-d=5-30=-25,
a10=a1+9d=-25+9*30=245,
S10=10(a1+a10)/2=5(-25+245)=1100
№9
1)x1=0, x2=2, x3=6, x4=10
2)c∈(-∞;-5)U(3;+∞) нет корней,
c∈{5}U(0;3] один кореньб
с∈{0}U(-5;-4) два корня,
с∈{-4}U(-3;0) три корня,
с∈(-4;-3] четыре корня
№10
(x^2+16x+28)^2+(x^2+11x-42)^2=0,
(x^2+16x+28)^2=0, x^2+16x+28=0, x1=-14, x2=-2,
(x^2+11x-42)^2=0, x^2+11x-42=0, x1=-14, x2=3,
x=14