first you need to set up an equation. if luis age is equal to four years added to colleens age we can substitute colleens age with a variable (i’m gonna use the letter c) and luis’s age for a different variable (i’ll use L). your equation would be C + 4 = L. our second equation would be both of their ages is equal to 52, giving us C + L = 52 as our equation. since our other equation tells us that what L equals (it would equal C plus 4), we can substitute out the L in the second equation for C + 4. the equations would change from C+L= 52, to C + C + 4 = 52. then we would solve like any regular equation for our variable. first we can simplify the 2 c’s together to get
2c + 4 = 52. next you would take your + four and do the opposite sign to both sides of the equation. so you do + 4 minus 4 and then 52 minus four. this leaves you with the equation 2c = 48. lastly you do the opposite function to both sides with your coefficient. you would do 2c divides by 2 (to cancel out your two because it’s being multiplied by c). and then 48 divided by 2 leaving you with C = 24. that tells us that colleens age is 24, and then you plug this into your first equation to get 24 + 4 = L telling you that luis’s age is 28. to fact check you would just add the two ages together to see if you got your total
number. these are called like two step equations with substitution i believe