The correct answer would be B.6 and 7
The 3 in "513" is only 3. it's 1, 2, 3. If we do 3 x 10 it's 30
<em>D. [ 6 10
</em>
<em>-8 0]</em>
<em>would be the correct answer.</em>
Set up the following equations:


x represents car A's speed, and y represents car B's speed.
We'll use elimination to solve this system of equations. Multiply the first equation by 7:


Combine both equations:

Divide both sides by 28 to get x by itself:

The speed of car A is
80 mph.Since we now know the value of one of the variables, we can plug it into the first equation:


Subtract 160 from both sides.

Divide both sides by 2 to get y by itself:

The speed of car B is
60 mph.