Hi, Peg,
Convert the words into equations. Let X be the larger and Y the smaller. Since we have two unknowns, we need at least 2 equations to find an answer. Here's how to translate the words into equations:
"Sum of 2 numbers is 84" is written in line 1
"The first is nine more than four times the second." is line 2
We have two equations, so let's see if we can eliminate one of the two variables by using one equation in the second. I get line 3 from line 1, which tells us the value of X based on Y. Now we have a definition of X that we can use in the second (line 2) equation. Line 4 shows how we substituted the new definition of Y. Now we only have X in the equation, so solve for X as shown in lines 5 - 7.
Since we now have X, use it's value in the line 3 equation and solve for Y, as shown in lines and and 9.
Line 10 checks the results, successfully.
Bob
