View Full Version : Find the pattern. 75 x 75 = 5,625 45 x 45 = 2,025 95 x 95 = 9,025 65 x 65 = ?
Foxhouse
Aug 10, 2010, 06:11 AM
I need to find the pattern in order to find the last product without multiplying. Thanks
ROLCAM
Aug 10, 2010, 06:30 AM
1) 7*(7+1) = 7*8 = 5,625
2) 4*(4+1) = 4*5 = 2,025
3) 9*(9+1) = 9*10 = 9,025
4) 6*(6+1) = 6*7 = 4,225
For this to work,the first digits must be equal and the addition of the two second digits must equal to 10.
Foxhouse
Aug 10, 2010, 06:39 AM
1) 7*(7+1) = 7*8 = 5,625
2) 4*(4+1) = 4*5 = 2,025
3) 9*(9+1) = 9*10 = 9,025
4) 6*(6+1) = 6*7 = 4,225
For this to work,the first digits must be equal and the addition of the two second digits must equal to 10.
Thank you so much! Foxhouse
ebaines
Aug 10, 2010, 06:40 AM
Given a number A5, where A is a single digit, when you square it the first digits of the answer are always equal to the A^2 + A, and the last two digits are always 25. So for example, for 35^2. we set A = 3, and the first digits of the answer are 3^2+3 = 12. So: 35^2 = 1225.