If the denominator of 5/7 is increased by a number and the numerator is doubled, the result is 1. Find the number.

3

Step-by-step explanation:

let n be the number, then

= 1 ← multiply both sides by 7 + n

10 = 7 + n ( subtract 7 from both sides )

3 = n

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons

1. 8

2. 9

3. 20

4. 3

5. 17

6. 2.2

7. 11.25

8. 1

9. 14

10. 2

step-by-step explanation:

thats the first half