#7/ Step by step please

Question

Michael is 17 years older than John. In what 4 years, the sum of their ages will be 49. Find Michael's present age

Answer 1

let x  = michaels age 

let y = johns age

 

x =17 + y             michael's age is 17 years older than john

x+4 +y+4 = 49    in 4 yrs, so we need to add 4 to both of their current age, the sum is 49 

 

from here you need to substitute the first equation into the second

 

(17+y)+4+y+4 = 49 

17+8 +2y = 49 

25+2y = 49 

2y = 49-25

2y = 24

y = 12

 

so Johns age is 12, use that to solve for x, Michaels Age

 

x= 17 + y 

x = 17+12

x = 29 

 

Michaels age is 29 

 

self check: use the second equation

 

x+4 +y+4 = 49

(29+4) + (12+4) = 49 

33+16 = 49 

49 = 49