Hello from MrBillDoesMath!
Answer:
-164 and -288 is one set of numbers that satisfies the equations
Discussion:
Let the number be x and y, Then
x/y = 4/7
=> 7x = 4y. (*)
and
x - y = 123
=> 7x - 7y = 123*7 (**) => multiply both sides by 7
Substitute the value of 7x from (*) into (**)
7x - 7y = 123*7 => substitution
4y - 7y = 123*7 => simplify. 4y -7y = -3y
-3y = 123*7 => divide both sides by -3
y = -(123/3)* 7 => 123/3 = 41
y = -41*7 = -288
As x - y = 123 ( and y = -288),
x - (-288) = 123 =>
x +288 = 123 => subtract 288 to both sides
x = 123 - 288 = -164
Thank you,
MrB
