7/8=0,875
1/2=0,5
i²=-1
1) z1+z2=(0,875+1)+(-1/2-1/2)i=1,875-i
2) (0.875-0.5i)(1-0.5i)=0.875-0.5i-0.4375i+0.25i²=
(0.875-0.25)+(-0.4375-0.5)i=0.625-0.9375i
10×-5-7-×=0
9×-12=0
9×=0+12
9×=12
×=12/9
sokrawaem na 3
x=4/3
((sin²17+sin²(90-17))/4-1/2cos60=(sin²17+cos²17)/4-1/2*1/2=1/4-1/4=0
sin 37·cos 8+cos 37·sin 8 = sin (37+8) = sin 45 = 0,5·√2