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 ▸Prove that the square of an odd number is always 1 more than a multiple of 4
Find the two points of intersection of the graphs y=x2 and y=x+2.
a). Solve x-4=13, b). solve 7y=35 c). solve 3w-9=27
There are 6 orange sweets and n total sweets in a bag. The probability of picking two sweets one at a time randomly and both being orange is 1/3. Show that n^2 - n - 90 = 0