A/(a²-ab)-b/(a²-b²)=a/a(a-b) -b/(a-b)(a+b)=1/(a-b) -b/(a-b)(a+b)=(a+b-b)/(a²-b²)=
=a/(a²-b²)
a=√2 b=√5
√2/(4-5)=-√2/3
3x(x-7)-x(4+3x)=5
3x²-21x-4x-3x²=5
-25x=5
x=5/-25
x=-0,2
2х²+14х=0
х(0,--14/2)
=(0,--7)
1)у¹=7^x * ln7 * ln(2x+3)+ 7^x * 1/(2x+3) * 2