1 and 1 / 3-7 / 12 + 9 / 20-11 / 30 + 13 / 42-15 / 56, then what is the negative reciprocal of N?

1 and 1 / 3-7 / 12 + 9 / 20-11 / 30 + 13 / 42-15 / 56, then what is the negative reciprocal of N?

1 and 1 / 3-7 / 12 + 9 / 20-11 / 30 + 13 / 42-15 / 56
=1+1/3-1/3-1/4+1/4+1/5-1/5-1/6+1/6+1/7-1/7-1/8
=1-1/8
=7/8
What's the negative reciprocal of N? It's - 1 / n

14.37×7.88-9.37×7.38＋1.437×21.2-93.7×0.262

14.37×7.88-9.37×7.38＋1.437×21.2-93.7×0.262=14.37×7.88-9.37×7.38＋14.37×2.12-9.37×2.62=14.37×(7.88+2.12)-9.37×(7.38+2.62)=14.37×10-9.37×10=(14.37-93.7)×10=5×10=50

14.37 by 7.88-9.37 by 7.38 + 1.437 by 21.2-93.7 by 0.262

14.37*7.88—9.37*7.38+1.437*21.2—93.7*0.262 1.437*78.8-93.7*0.738+1.437*21.2-93.7*0.2621.437*( 78.8 + 21.2)---93.7(0.738+0.262)1.437*100---93.7143.7-93.7=50

Use the plus, minus, multiply and parentheses to make the result 21
12, 7, - 9 and 1, 15, 1.2, 7
Don't be with me

(12+(-9))*7
15*(1.2-1)*7