8. An Introduction to Equations
Sign In
Use mental math to guess the starting value for the table.
6
8a-10=38 In order to choose a good starting point for our table, let's pretend that the equation is 8a=38. What multiplied by 8 would get us close to 38? 4 or 5 would be equally valid, so let's try those. We should also try one digit less and one digit greater, just to be safe.
a | 8a-10 | = |
---|---|---|
3 | 8 (3)-10 | 14 |
4 | 8 (4)-10 | 22 |
5 | 8 (5)-10 | 30 |
6 | 8 (6)-10 | 38 |
We can see that a=6 is the solution to our equation.