<span> а)5 3/5*1 4/21=28/5*25/21=28*25/5*21=20/3=6 2/3</span>
<span> б)32*5/24= 20/3= 6 2/3</span>
<span> в)12/35*2/5 = 12*2/35*5=24/175</span>
2.
1) а1 = -2
а2 = -2 + (-4) = -6
а3 = -6 + (-4) = -10
а4 = -10 + (-4) = -14
а5 = -14 + (-4) = -18
2) а1 = -2
а2 = -2 × (-4) = 8
а3 = 8 × (-4) = -32
а4 = -32 × (-4) = 128
а5 = 128 × (-4) = -512
Z1+z2=8-2i
z1*z2=(5-4i)(<span>3+2i)=15+10i-12i-8i^2=15-2i+8=23-2i</span>