Calculate (7 + √3)(7 - √3)
(7 + √3)(7 - √3) = 72 + 7√3 - 7√3 - (√3)2 = 49 - 3 = 46Alternatively you can go straight to identifying that this is the difference between two squares, using the fact that (a + b)(a - b) = a2 - b2
IB
Related Maths GCSE answers
All answers ▸Factorise x^2+2x-8
Matt had 3 piles of coins, A, B and C. Altogether there was 72p. Pile B had twice as much as pile A. Pile C had three times as much as pile B.
Solve algebraically the simultaneous equations: x^2 + y^2 = 25 and y – 3x = 13
If a rectangle has sides (x+3) and (2x-1) and an area of 15, find x and the length of each side.