(х+3)(3х+1)-(2х-3)(1-х),при х=-0,6​

(х+3)(3х+1)-(2х-3)(1-х)=

3х^2+х+9х+3-2х+2х^2+3-3х=

5х^2+5х+6= 5×(-0.6)^2+5×(-0.6)+6=

5×0.36 - 3 + 6= 18 + 3= 21