The sum of the digit of a certain two digit number is 13 and the number is 2 more than 7 times the units digit.find the number.

Question

word problems involving simultaneous equation

Answer 1

Let the number be 10a+b. So a+b=13, a=13-b; 10a+b=7b+2, 10a=6b+2, 5a=3b+1. So 5(13-b)=3b+1, 65-5b=3b+1, 8b=64, b=8, and a=5. The number is 58.

Answer 2

In ordinary numerical digits, what is 67 more than the sum of the two-digit numbers s.i._x___s.i._x and .e._i_g.h.t___n._i.n_e?