Question

The sum of two numbers is 52. The greater number is 4 more than the smaller number. Which equation can be used to solve for the smaller number?

Answer 1

Let x be the smaller number.
How would you write the larger number in terms of x?

Answer 2

let larger no. be y
then y = x+4(given) and x+y =52 (given)
use both to find x

Answer 3

"The greater number is 4 more than the smaller number" translates into "y=x+4"

You now have a "system of linear equations."

Solve simultaneously:

y=x+4
x+y=52

Methods of solving such a system include (among others):

graphing, elimination by addition/subtraction, substition, matrices.