● -умножить, /- разделить чертой
1) 64/10 : 80/3=64/10 ● 3/80= 192/800=cокращаем=6/25
6/25+1/8=60/250 +450/250=510/250=сокра.=2,04
2) 5 : 4/25=4/5
4/5+2/3=12/15 +10/15=22/15
22/15 ● не понятно дальше
3) 41/18-17/36=1478/648 - 306/648=1170/648
1170/648 ● 18/65=сокращаем=9/18=1/2
8/7-23/49=392/343-161/343=231/343
231/343:91/49= 231/343: 49/91=11319/31213
11319/31213+7/6=67914/187278+218491 /187278 =286405/ 187278=
=1,5
1,5+1,2=2,7
( 4X + 1)^2 = ( X + 4)^2
16X^2 + 8X + 1 = X^2 + 8X + 16
16X^2 - X^2 + 8X - 8X = 16 - 1
15X^2 = 15
X^2 = 1
X1 = 1
X2 = - 1
5Y = X^2 + 8X + 16
5Y = 1 + 8 + 16 = 25
Y1 = 5
5Y = 1 - 8 + 16 = 9
Y2= 9/5 = 1,8
ответ ( 1 ; 5 ) ; ( - 1 ; 1,8 )