8. An Introduction to Equations
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Use mental math to guess the starting value for the table.
-1
0=10+10y In order to choose a good starting point for our table, let's pretend that the equation is 0=10y. What multiplied by 10 would get us close to 0? 0 is a good guess, so let's try it in our table. We should also try one digit less and one digit greater, just to be on the safe side.
y | 10+10y | = |
---|---|---|
1 | 10+10 (1) | 20 |
0 | 10+10 (0) | 10 |
-1 | 10+10 (-1) | 0 |
We can see that y=-1 is the solution to our equation.