Question

12+12=9 25+25=49 18+18=81 29+29=?

Answer 1

18+18=81
(1+8)²=1²+8²+2×(1×8)
          =1+64+16
 18+18 =81
29+29=(2+9)²
          =2²+9²+2(2×9)
          =4+81+36
29+29=121

Answer 2

Answer:

The next number in the sequence is 121.

To find:

To find the next number in the given sequence

Solution:

$\begin{array} { l } { 12 + 12 = 9 \Rightarrow 1 + 2 = 3 \Rightarrow 3 \times 3 = 9 } \\ \\{ 25 + 25 = 18 \Rightarrow 2 + 5 = 7 \Rightarrow 7 \times 7 = 49 } \\\\ { 18 + 18 = 81 \Rightarrow 1 + 8 = 9 \Rightarrow 9 \times 9 = 81 } \\\\ { 29 + 29 = ? \Rightarrow 2 + 9 = 11 \Rightarrow 11 \times 11 = 121 } \end{array}$

Therefore, the next number in the sequence is 121.