Question

a)(c-9)(c+9)-(c+4)(c-4)=

б)(7c+2)(7c-2)-(7c-5)(7c+5)=

в)(3c+1)(1-3c)+(3c-8)(8+3c)=

г)(0,3c+1,1)(1,1-0,3c)+(0,3c-0,2)(0,2+0,3c)=

Answer 1

a) (c-9)(c+9)-(c+4)(c-4)=c^2+9c-9c-81-c^2+4c-4c+16=-65

 б)(7c+2)(7c-2)-(7c-5)(7c+5)=49c^2-14c+14c-4-49c^2-35c+35c+25=21

в)(3c+1)(1-3c)+(3c-8)(8+3c)=3c-9c^2+1-3c+24c+9c^2-64-24c=-63

г)(0,3c+1,1)(1,1-0,3c)+(0,3c-0,2)(0,2+0,3c)=0.33c-0.09c^2+1.21-0.33c+0.06c+0.09c^2-0.04-0.06c=1.17