42×21=
To solve this multiplication of fractions problem, we will follow these steps:
Now, let's carry out these steps:
Step 1: Multiply the numerators: .
Step 2: Multiply the denominators: .
Step 3: The resulting fraction is . We simplify by dividing the numerator and the denominator by their greatest common divisor, which is 2. So, .
Therefore, the solution to the problem is .