Answer:
The first number is 69.
Step-by-step explanation:
step 1. Let x be the second number. Let 9+4x is be first number.
Step 2. x+9+4x=84 The sum of two numbers is 84.
Step 3. Simplify: 5x+9=84.
Step 4. Subtract 9 to both sides of equation: 5x+9-9=84-9=75
Step 5. Simplify and divide by 5: 5x=75 or x=15. Then 9+4x=9+4(15)=69
Step 6. The first number is 69.
I hope the above steps were helpful.
