Question

viết dưới dạng 1 tích a)9-4x^2 b)16^2-25 c)a^4 -16 d)(a+b)^2-1

Answer 1

\(\left(a\right):9-4x^2=3^2-\left(2x\right)^2=\left(3-2x\right)\left(3+2x\right)\)

\(\left(b\right):16x^2-25=\left(4x\right)^2-5^2=\left(4x-5\right)\left(4x+5\right)\)

\(\left(c\right):a^4-16=\left(a^2\right)^2-4^2=\left(a^2-4\right)\left(a^2+4\right)\\ =\left(a^2-2^2\right)\left(a^2+4\right)=\left(a-2\right)\left(a+2\right)\left(a^2+4\right)\)

\(\left(d\right):\left(a+b\right)^2-1=\left(a+b\right)^2-1^2=\left(a+b-1\right)\left(a+b+1\right)\)