If 1+2=7; 3+4=31;5+6=71; 7+8=127 then 9+10=?

Question

If
5 + 4 => 9
3 + 5 => 9
9 + 1 => 9
1 + 6 => 8
4 + 2 => 8
1 + 7 => 7
5 + 6 => 6
3 + 7 => 3
7 + 0 => 0
Then
8 – 1 => ??

Answer 1

199
(a*b*2)+(a+b)=c
9*10*2=180
180+9+10=199

Comments

1+2=7, 1+2=3, 7-3=4, 4=4x1 (1) / 3+4=31, 3+4=7, 31-7=24, 24=4x6 (6) / 5+6=71, 5+6=11, 71-11=60, 60=4x15, (15) / 7+8=127, 7+8=15, 127-15=112, 112=4x28 (28) , so, 6-1=5, 15-6=9, 28-15=13, (so 9-5=4, 13-9=4,) so, 9+10=19, then if answer is x, so x-19=180 i.e(45x4), so, x=199

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(10^2) * 2 - 1

Answer 2

(a+b)*b+a

a=9 ,b=10

199

Comments

then how you will get:
5+6=71

using the same rule.
??

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Its working on that also
a=5 b=6 then
(5+6)*6+5 = 11*6+5 = 66+5 = 71

Answer 3

2*n^2 +4*n +1 = 162+ 36+ 1 = 199, where n= 9

Answer 4

(1+2)*2 + 1 = 7
(3+4)*4 + 3 = 31
(5+6)*6 + 5 = 71
(7+8)*8 + 7 = 127
(9+10)*10 + 9 = 199

Ans :- 199

Comments

How did you come up with this? Because I came up with a totally different way. I just wanted to know what made you realize that.

Answer 5

1+2= 1+(1+2)*2 = 7
3+4= 3+(3+4)*4 = 31
5+6= 5+(5+6)*6 = 71
7+8= 7+(7+8)*8 = 127
9+10= 9+(9+10)*10 = 199

so, 199 is the answer.

Answer 6

y*y+x*x+y+(y-2)
2*2+1*1+2+(2-2)=7
4*4+3*3+4+(4-2)=31
6*6+5*5+6+(6-2)=71
8*8+7*7+8+(8-2)=127
10*10+9*9+10+(10-2)=199

Answer 7

a*a+b*b + (a+b-1)=9*9+10*10+(1+10-1)=181+18=199

Answer 8

here right side= a(a+2)+b^2

1+2= 1*3+2^2=3+4=7

3+4=3*5+4^2=15+16=31

5+6=5*7+6^2=35+36=71

hence
9+10=9*11+10^2=99+100=199
answer=199