8х-1.79=4.61-8х, 8х+8х=4.61+1.79, 16х=6.4, х=6.4:16, х=0.4. ПРОВЕРКА:8*0.4-1.79=4.61-8*0.4, 3.2-1.79=4.61-3.2, 1.41=1.41.
А)
=3×(-1)^2-5×(-1)+4=3+5+4=12
б)
=-0.4×(-5)^3+2.5×(-8)=50-20=30
(x-xc)/(xd-xc)=(y-yc)/(yd-yc)
(x-(-1))/(3-(-1))=(y-(-3))/(4-(-3))
(x+1)/4=(y+3)/7
y=1.75x-1.25