Question

12. What number should be added to (-5/7) to get (-2/3)?

13. What number should be subtracted from (-5/3) to get (5/6)?

14. What should be added to ((1/2) + (1/3) + (1/5)) to get 3?​

Answer 1

Answer:

12. Solution:let the unknown value be x

x+-5/7=-2/3

7x+(-5)/7=-2/3

3(7x-5)=7*2

3(7x-5)=-14

3*7x3*5=-14

21x-15=-14

21x=1

x=1/21

13.Solution:

-5/3-x=5/6

(-5)-3x/3=5/6

-3x-5/3=5/6

x=-5/2

14.Solution:

x+1/2+1/3+1/5=3

(2*3*5)x+15+10+6/2*3*5=3

30x+15+10+6/2*3*5=3

30x+31/2*3*5=3

30x+31/30=3

30x+31=30*3

30x+31=90

(30x+31)+(-31)=90+(-31)

30x+31-31=90-31

30x/30=59/30

x=59/30