Решение
AB = √[(- 1 - 2)² + (3 - 7)²] = √(9 + 16) = √25 = 5
1)3-5/7x=1-3/7x
21x-5 /7x=7x-3 /7x
7x(21x-5)=7x(7x-3)
21x-5=7x-3
21x-7x=-3+5
14x=2
X=1/7
2)1/8x -2=5/8x +1
1-16x/8x=5+8x/8x
8x(1-16x)=8x(5+8x)
1-16x=5+8x
-16x-8x=5-1
-24x=4
X=-1/6
D(y)=R
y'(x)=3x^2-3
D(y')=R
y'(x)=0
3x^2-3=0
x^2=1
x=1
x=-1
-3<=x<=3
x=1
x=-1
y(-3)=-27+9+8=-10
y(3)=27-9+8=26
y(-1)=-1+3+8=10
y(1)=1-3+8=6
На отрезке [-3;3]
унаиб.=у(3)=26
унаим.=у(-3)=-10
{8x+3y=31|*5
{6x-5y=45|*3
{40x+15y=155
{18x-15y=135
18x-15y+40x+15y=135+155
58x=290|:58
x=5
8*5+3y=31
3y=31-40
3y=-9|:3
y=-3
Ответ: х=5; у=-3