Grace solved the equation 122 = x - 58. Her work is shown.

x = -180

Step-by-step explanation:

From the question, 122 = x - 58

Step 1: To find x, we have to make x the subject of the formula

x = -58 - 122

x = -180

51

step-by-step explanation:

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

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional