If 7 pencils cost $4.20, then 3 pencils costs
$0.60
$1.80
$12.60
$29.40

b. $1.80

4.20 ÷7 =.60

Each pencil calls 60 cents 60 × 3 is 180 So 3 pencils cost $1.80

move it to the other side

step-by-step explanation:

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: