What multiplication tables should every student memorize.

1-15

Step-by-step explanation:

You should at least teach students 1-15 or 1-20

take the logarithm of both sides (the base of the log doesn't matter):

apply the exponent property - this says that :

distribute the log terms on both sides:

group like terms together:

divide through both sides by the coefficient on :

you can do some additional rewriting here using the properties of the logarithm to simplify things if you like:

3boys + 4 girls = 7 students

3 boys to students   true   yes

4 girls to 3 boy   true     yes

3 boys to 7 girls   false   no

4 girls to 7 students   true   yes