X square - 4 x minus 21 July 8, 2019 16 32 64 128 X square 4 x minus 21 is equal to X square 4 x minus 21 factorise X square 4 x minus 21 is equal to zero X square 4 x minus 21 by x 7 4 x square 8 x minus 21 is equal to 4 x square 8 x minus 21 barabar 4 x square 8 x minus 21
