Answer:
x+(x+3)=37
Step-by-step explanation:
'x' is david's age, and since Martin is 3 yrs older then david's age, in this case 'x', we can write martin's age as 'x+3'. And since their ages combine to 37, hence the equation x+(x+3)=37
SOLVED EQUATION (remember you have to isolate the unknown)
x+(x+3)=37
x+x+3=37
2x+3=37
2x+3-3=37-3
2x=34
2x/2=34/2
x=17
17 yrs is David's age
x+3 ---- 17+3=20
20 yrs is Martin's age
