Math - System of Equations

Question

Bob is trying to guess the two numbers his friend is thinking of. His Friend tells him the sum of the two numbers is 25. He also tell him that the bigger number is 5 more than the smaller number. solver this using the substitution method. Check your answer. PLEASE HELP ASAP THANKS

Answer 1

So let's say the two numbers Bob is thinking of is x and y. His friend says the sum is 25, so we have our first equation: x+y = 25

 

The second thing he tells Bob is that the bigger number is 5 more than the smaller number. We can randomly decide which one is the smaller one. Let's say x is the smaller one, so x+5 = y.

 

We now know that y = x+5. Substitute y in the first equation for x + 5, we get:

x+ (x+5) = 25

 

Simplify:

2x + 5 = 25

 

Subtract 5 on both sides:

2x = 20

 

Solve for x

x = 10