42 cm because if you divide 210 and 1260 it will make 6 so u just multiply it by 7 and u get 42
Answer:
reflection is defined as the change in the direction of a wavefront at the interface between two different media, bouncing the wavefront back into the original medium. A common example of reflection is reflected light from a mirror or a still pool of water, but reflection affects other types of waves beside light.
Step-by-step explanation:
I'm thinking this is what the problem looks like:

. The first thing to do is to move the

over to the other side because it has a common denominator with the other side. Doing that and at the same time combining them over their common denominator looks like this:

. The best way to solve for x now is to cross-multiply to get 3(4-x)=-4(x-4). Distributing through the parenthesis is 12 - 3x = -4x + 16. Solving for x gives us x = 4. Of course when we sub a 4 back in for x we get real problems, don't we? Dividing by zero breaks every rule in math that there ever was! So, yes, the solution is extraneous.
40; base it off of the y-intercept [C]. What is the unit of measurement?