10y+2*(7y-2)=26-4x
10y+14y-4=26-4x
24у-4=26-4х
4(6у-1)=4(6,5-х)
6у-1=6,5-х
х=6,5+1-6у
х=7,5-6у
Lim(x→0)(1-cos(3x²))/(x²-cos(x²/4)
Используем правило Лопиталя:
lim(x→0)(-cos(3x²)+1)`/(x²-cos(x²/4))`=lim(x→0)(sin(3x²)*6x)/(2x+sin(x²/4)*(x/2)=
lim(x→0)(sin(3*x²)*6*x)/((x/2)*(4+sin(x²/4))=
=lim(x→0)(12*sin(3*x^2)/(4+x*sin(x²/4))=12*sin(3*0²)/(4+sin(0²/4)=
=12*sin0/(4+sin0)=0/4=0.
33-9 19/34=27 33/34 вот правильное решение
(600:30-7)*5-(24-4*4)*(32:16)+60:4*10=(20-7)*5-(24-16)*2+15*10=13*5-8*2+150=65-16+150=199
500-(28*5+25*4-120:2):6-(28:14+420:140)*30=500-(140+100-60):6-(2+3)*30=500-280:6-5*30=500-150-46,7=303,3