Explanation:
1)
Prime factorization of 36 is: 2 x 2 x 3 x 3.
Prime factorization of 196 is: 2 x 2 x 7 x 7.
Prime factorization of 361 is: 19 x 19.
2)
Greatest Common Factor of 126 and 144 is: 18.
Least Common Multiple of 28, 42, and 63 is: 252.
3)
2/3+3/4=17/12.
2/3-3/4= -1/12.
3 2/3 x 1 3/4 = 6 5/12.