Answer:
A and C
Step-by-step explanation:
B has a solution and D is 0. A and C are the only ones with no solution.
9514 1404 393
Answer:
11
Step-by-step explanation:
4 × (2 3/4) = 4×2 + 4×(3/4) = 8 + 3 = 11
or
4 × (2 3/4) = 4 × 11/4 = 11
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.
In general, any equation like
(assuming
) is solved by

So, in your case, the solution is

Dividing by a fraction means to multiply by the inverse of that fraction:
