In a defined operation *, for any numbers s and t, the expression is given by s*t = (s - 2)(t + 2). If (-3)*y = -20, what is the value of y?
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This is exactly what I needed to practice
Great!
thanks
thanks, this one was pretty straightforward once I remembered to plug in -3 for s and y for t
yeah same, I overthought it at first lol
did you distribute or just plug in? I plugged in and it was fast
wait I got y = 2 but let me double check... (-3-2) = -5 and (y+2), so -5(y+2) = -20, that gives y+2 = 4, y = 2. nice
your steps make sense, I did the same thing
quick q - does the operation go left to right only? i assumed s is the first number and t is second
yes, s*t means s is first, t is second, just match it to the formula
same here, just make sure you don't flip them
What it tests
Your ability to evaluate and compose functions, including unusual defined operations.
Common trap
Applying function operations in the wrong order or ignoring domain restrictions.