B1 Khai triển những đẳng thức sau:
(3a - 1)2
(a - 2)2
(1 - 5a)2
(3a - 2b)2
(4 - 3a)2
(5a - 4b)2
(5a - 3b)(5a + 3b)
(3x + 1)(3x - 1)
(5x2 - 2)(5x2 + 2)
(2a + 1/2)(2a - 1/2)
(3x2 - y)(3x2+ y)
(1/2x - 1)(1/2x + 1)
(3/4x + 2)(3/4x - 2)
(5x - 3/2)(5x + 3/2)
(2a2 - 7)(2a2 + 7)
các bạn giúp mình giai những bài này nha
mik cần gấp
2
\(\left(3a-1\right)^2=9a^2-6a+1\)
\(\left(a-2\right)^2=a^2-4a+4\)
\(\left(1-5a\right)^2=1-10a+25a^2\)
\(\left(3a-2b\right)^2=9a^2-12ab+4a^2\)
\(\left(4-3a\right)^2=16-24a+9a^2\)
\(\left(5a-4b\right)^2=25a^2-40ab+16b^2\)
\(\left(5a-3b\right)\left(5a+3b\right)=25a^2-9b^2\)
\(\left(3x+1\right)\left(3x-1\right)=9x^2-1\)
\(\left(5x^2-2\right)\left(5x^2+2\right)=25x^4-4\)
\(\left(2a+\dfrac{1}{2}\right)\left(2a-\dfrac{1}{2}\right)=4a^2-\dfrac{1}{4}\)
\(\left(3x^2-y\right)\left(3x^2+y\right)=9x^4-y^2\)
\(\left(\dfrac{1}{2}x-1\right)\left(\dfrac{1}{2}x+1\right)=\dfrac{1}{4}x^2-1\)
\(\left(\dfrac{3}{4}x+2\right)\left(\dfrac{3}{4}x-2\right)=\dfrac{9}{16}x^2-4\)
\(\left(5x-\dfrac{3}{2}\right)\left(5x+\dfrac{3}{2}\right)=25x^2-\dfrac{9}{4}\)
\(\left(2a^2-7\right)\left(2a^2+7\right)=4a^2-49\)
