Sum of two number is 72. One number is 30 more than the other. Let x be the smallr number and y be the bigger number. Write an Equation.

x + (x+30) = 72

Step-by-step explanation:

if x is the smaller number and y is the bigger number, then according to the condition (one number is 30 more than the other) y=x+30.

It the sum of the two numbers is 72, then x+y=72.

After substitution y=x+30:

x + (x+30) = 72; - the required equation.

⇔ 2x=42; ⇒ x=21 (it is the smaller number)

y=51 (it is the bigger number).