Question

$15a^2+7a-2/4-9a^2$СОКРАТИТЕ ДРОБЬ!

4-9a^2 ---это под всей дробью

Answer 1

15a^2+7a-2=0,

D=169,

a1=2/3, a2=1/5,

15a^2+7a-2=15(a-2/3)(a-1/5)=(3a-2)(5a-1),

(15a^2+7a-2)/(4-9a^2)=(3a-2)(5a-1)/((2+3a)(2-3a))=-(3a-2)(5a-1)/((2+3a)(3a-2))=-(5a-1)/(2+3a)=(1-5a)/(2+3a)