4*7=28

9*16= 144

so you get the fraction 28/144

simplify by diving by a common number (4) and you get your answer: 7/36

2) find the LCD (least common denominator) which is 15

so you get 12/15 – 10/15

subtract the numerators so you get 2/15.

for number 2, you have to find a common denominator.

both 5 and 3 go into 15 so that is your common denominator. Its 15 because that is the lowest number that both go into. you ahve to multiply top and bottom of hte fraction by the same number so 4/5 in order to make the bottom 15 you have to times it by 3 and that means you have to times 4 by three. your new fraction becomes 12/15. the same thing for 2/3. to make the denominator 15, you have to times it by 5 and then you must times 2 by five to keep it proportional. so the new fraction is 10/15. now to subtract, you keep the same denominator and just subtract the numerator. 12-10 is 2 so the answer is 2/15.

= (4 x 7)/( 9 x 16)

= 28/144

= 7/36 (reduced)

2. 4/5 – 2/3 (find the lowest common denominator in this case 15)

= 12/15 – 10/15

= 2/15

2) 4/5 – 2/3 (the same as 12/15-10/15)= 2/15