Question 1083732
let a = the 1st number
let b = the 2nd number
:
Write an equation for each statement
"The first of two numbers is 7 more than the second number."
a = b + 7
" When the first number is doubled, it is 3 times the second number."
2a = 3b
 Find the numbers.
Replace a with (b+7) in the 2nd equation
2(b+7) = 3b
2b + 14 = 3b
14 = 3b - 2b
 14 = b
then obviously a = 21
:
;
Check solutions in the 2nd equations: 2(21) = 3(14)