Answer:
Explanation:
t + u = 11 ----------- (1 )
10t + u = 10u + t - 9
10t + u - 10u - t = -9
10t - t + u - 10u = - 9
Combine like terms
9t - 9u = -9
Divide the entire equation by 9

t - u = -1 --------------(2)
Add equation (1) & (2) and so, u will be eliminated and we can find the value of t
(1) t + u = 11
(2) t - u = -1
2t = 10
t = 10/2
t = 5
Plugin t = 5 in equation (1)
5 + u = 11
u = 11 - 5
u = 6
The original number is 56