The difference of two numbers, a and b, is 21. The difference of 5 times a and two times b is 18. What are the values of a and b?
A. 4,1
B. -19,40
B. 20,1
C. 30,9
D. -8,-29

Question

The difference of two numbers, a and b, is 21. The difference of 5 times a and two times b is 18. What are the values of a and b?
A. 4,1
B. -19,40
B. 20,1
C. 30,9
D. -8,-29

anonymous · Answer

This is what I got

ifference of two numbers is 21: 

a - b = 21 

difference of 5 times a and 2 times b is 18: 

5a - 2b = 18 

we have a system of equations: 

a = 21 + b 

5a - 2b = 18 
5(21 + b) - 2b = 18 
105 + 5b - 2b = 18 
3b = -87 
b = -29 

Now that we have b, solve for a: 

a = 21 + b 
a = 21 + (-29) 
a = -8 

Your numbers are: 

-8 and -29

anonymous · Answer

Thank you so much ! (:

anonymous · Answer

You are very welcome! :)

anonymous · Answer

Do you think you can help me with another question?