Question

Answer 1

a) a²-4b²-a-2b
= (a-2b)(a+2b)-(a+2b)
= (a-2b-1)(a+2b)
b) 3x²-7x-6
= 3x²-9x+2x-6
= 3x(x-3)+2(x-3)
= (3x+2)(x-3)
c) 4x²+4a(b-a)-b²
= 4x²+4ab-4a²-b²
= -(4a²-4ab+b²)+(4x²)
= -(2a-b)²+(2x)²
= (2x-2a+b)(2x+a-b)
d) x⁴+4
Tham khảo: https://www.google.com/search?q=x%5E4%2B4&sxsrf=AOaemvKdbJM-h1SxCCqcAhJ_xIUM851Ozg%3A1639992314189&ei=-kvAYYCEC4mvoASO7ImwCg&ved=0ahUKEwiA6ci6h_L0AhWJF4gKHQ52AqYQ4dUDCA4&uact=5&oq=x%5E4%2B4&gs_lcp=Cgdnd3Mtd2l6EAMyBQgAEIAEMgUIABCABDIFCAAQgAQyBQgAEIAEMgUIABCABDIFCAAQgAQyBQgAEIAEMgcIABCABBAKMgUIABCABDIFCAAQgAQ6BwgAEEcQsAM6BwgjEOoCECc6BAgjECc6CwgAEIAEELEDEIMBOgsILhCABBCxAxCDAToICAAQsQMQgwE6CwguEIAEEMcBEKMCOggIABCABBCxAzoECAAQQzoECAAQA0oECEEYAEoECEYYAFDqEljlMGDmM2gDcAJ4AIABaogBmgSSAQM1LjGYAQCgAQGwAQrIAQjAAQE&sclient=gws-wiz

Answer 2

a, hông bt làm:>

\(b,3x^2-7x-6\)

\(=\left(3x^2-9x\right)+\left(2x-6\right)\)

\(=\left(x-3\right)\left(3x+2\right)\)

\(c,4x^2+4a\left(b-a\right)-b^2\)

\(=4x^2-4a\left(a-b\right)-b^2\)

\(=4x^2-4a^2+4ab-b^2\)

\(=\left(2x\right)^2-\left(4a^2-4ab+b^2\right)\)

\(=\left(2x\right)^2-\left[\left(2a\right)^2-4ab+b^2\right]\)

\(=\left(2x\right)^2-\left(2a-b\right)^2\)

\(=\left(2x-2a-b\right)\left(2x+2a-b\right)\)

\(d,x^4+4\)

\(=\left(x^2\right)^2+2^2\)

\(=\left(x^2+2\right)^2-2x^22\)

\(=\left(x^2+2\right)^2-4x^2\)

\(=\left(x^2+2\right)^2-\left(2x\right)^2\)

\(=\left(x^2+2+2x\right)\left(x^2+2-2x\right)\)