Ответ:
Объяснение:
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1)(38/10-1/2)×4/3=(38/10-5/10)×4/3=35/10×4/3=
=14/3=4 2/3
2)-14÷14/5-5=-14/1×5/14-5=-10
-72/10-20/10. -92/10. 92
3)-------------------= -------= ---=1 23/69
-6,9. -69/10. 69
4)(103/12-89/36)×2,7-13/2×100/65=220/36×27/10-
-10=66/4-10=66/4-40/4=2,6
5)0,5×(0,8-(-1,4))=0,5×2,2=1,1
36+12у+у^2-81=0
у^2+12y-45=0
y^2+15y-3y-45=0
y(y+15)-3(y+15)=0
(y+15)*(y-3)=0
y1+15=0
y2-3=0
y1=-15
y2=3