5x²-2x²+5x-11x-15-9
3x²-6x-24=0
D=√6²-4*3*-24=√36+288=√324=18
x1=6+18/6=4
x2=-2
1) 8\9= 0.8 2) 2\3= 0.6 3)0.6*1.7= 1.02 <span>4)0.8 + 1.02=1.82 </span>
-3+(-6)=-9
................
1)3/(2x-y) - 2/(2x+y) - 1/(2x-5y)=
= (3(2x-5y)(2x+y)-2(2x-y)(2x-5y) - (2x-y)(2x+y))/(4x²-y²)(2x-5y)=
=(12x²+6xy-30xy-15y²-8x²+20xy+4xy-10y²-4x²+y²)/(4x²-y²)(2x-5y)=
=(-24y²-10xy)/(4x²-y²)(2x-5y)=-2y(12y+5x)/(4x²-y²)(2x-5y)
2)-2y(12y+5x)/(4x²-y²)(2x-5y) *(4x²-y²)/y²=-2(12y+5x)/(2x-5y)=2(12y+5x)/(5y-2x)