The Addition Property of Equality justifies Emily's first step. She added 9 to both sides, canceling out the minus 9 while keeping the equation equal.
Step-by-step explanation:
The average speed is distance over time.
34 mi / 0.5 hr = 68 mph
Therefore, the driver must have been speeding at some point between the two toll booths.
For 10 here is the answer and for 9 i’ll reply to my comment
Answer:
See attachment
Step-by-step explanation:
The given matrix equation is:

To find Matrix X, we need to multiply both sides of the equation by 2 to obtain:

This simplifies to;

By scalar multiplication, we multiply each entry in the matrix A by to 2 to obtain matrix X.