If these triangles are congruent, then side RS is congruent to side TV and that means that y = 4 - x. If y = 4-x, we can sub that into the next equation where side RV = side ST and 1 = 4x - y. If y = 4-x, we sub in accordingly to get 1 =4x - (4 - x). That simplifies to 1 = 4x - 4 + x which is, combining like terms, 5 = 5x. That means that x = 1. If x = 1, and y = 4 - x, then y = 4 - 1 and y = 3. There you go!
I think that the answers is b
Natural numbers are counting numbers. Natural numbers cannot be a fraction with a different numerator and denominator when simplified. Therefore 2/5 is not a natural number.
