In a question, when it states "a number" without giving a real number, that means it's a variable. Variables are normally letters. In the question, it gives you what letter to use, "y". Start the equation.
[tex] Current\ Equation: y [/tex]
The word "decreased" is used when subtracting. In this equation, you are going to be subtracting. Add that to the equation.
[tex] Current\ Equation: y- [/tex]
"Negative" is used for negative numbers. For example, "negative 1" is going to be -1. In the question, it says "negative 7", which is going to be -7. Add that to the equation.
[tex] Current\ Equation: y-(-7) [/tex]
The phrase "Is the same thing as" means equal. Add that to the equation.
[tex] Current\ Equation: y-(-7) = [/tex]
At last, 48. 48 is just 48 as a number. Add that to the equation.
[tex] Equation: y-(-7)=48 [/tex]
Your answer is: y - (-7) = 48
