4,28:0,2=21,4. ;
21,4-19,7=1,7
1,7•0,7=1,19
1,19-2,09=-0,9
(1.8-0.3y)*(2y+9)=0
1.8-0.3y=0 или 2y+9=0
0.3y= -1.8 2y= -9
y= -1.8/0.3 y= -9/2
y= -6 y= -4.5
(5y+4)*(1.1y - 3.3)=0
5y+4=0 или 1.1y-3.3=0
5y= -4 1.1y= 3.3
y= -4/5 y= 3.3/1.1
y= -0.8 y= 3
4/3Х +2/3 = 2Х -1
4Х + 2 = 3(2Х-1)
4Х +2 = 6Х -3
4Х -6Х = -3-2
-2Х = -5
2Х = 5
<u>Х = 2,5</u>
1.6(6.4² -3.6²) /0.4(2.4² -0.4²)=1.6(6.4-3.6)(6.4+3.6)
/ 0.4(2.4-0.4)(2.4+0.4) = 1.6(2.8*10) /0.4(2*2.8) = 4*10 /2 =2*10 =20
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