Question

(2а-5)в квадрате - 4 (4-а)(3+а), при а=1/12

Answer 1

(2a-5)ˇ2 -4(4-a)(3+a)=4aˇ2-20a+25-4(12+4a-3a-aˇ2)=
=4aˇ2-20a+25-48-4a+4aˇ2=
=8aˇ2-24a-23
8.(1/12)ˇ2-24.1/12-23=8/144 -2-23=1/18-25=1/18-450/18=-449/18