`12345679xx72` is equal to 88888888 (b) 888888888 898989898 (d) 999999998

12345679 xx 72 is equal to

b_(xy) xx b_(yx) is equal to

sqrt((.081xx.484)/(.0064xx6.25)) is equal to (a) 0.9(b)0.99 (c) 9(d)99

(0.09xx7.3) is equal to: 6(b)657(c)67(d).657

Work out the following multiplication. {:(" 12345679"),(" "xx" 9"),(ulbar(" ")):} Use the result to answer the following questions. (a) What will be 12345679 xx 45? (b) What will be 12345679 xx 63? (c) By what number should 12345679 be multiplied to get 888888888? (d) By what number should 12345679 be multiplied to get 999999999?

(7.5xx7.5+37.5+2.5xx2.5) is equal to (a) 30 (b) 60 (c) 80 (d) 100