Okay, I am doing this maths homework in Core 1 Proofing unit
The question asks me to decide if this conjecture is telling the truth.
IF it's true i have to prove it by suitable method and name the method
IF it isn't true, i have to come up with a counterexample
and the questions are as follows
1.The sum of any three consecutive integers is divisible by 6
2. An easy way to remember 7times 8 is that 56=7*8 and the number 5,6,7 and 8are consecutive. There is exactly one other multification of two single-digit numbers with the same pattern
3. x^2>x => x.1
4. ABCD is a parallelogram. Sides AB and DC are parallel; sides AD and BC are parallel. AC=BD
5. A triangle with sides (x^2+1), (x^2-1), 2x is right angled.
6. The circle with equation x^2+y^2=36 passes through exactly four points for which both the x and y coordinates are integers.
7. The value of (n^2+n+41) is a prime number for all positive integer values of n.
8.A number is divisible by 9 if the sum of its digits is divisible by 9.
9. n is prime, then n^2+n+1 is also a prime
thank you!