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:
Answer:
-4/3
Step-by-step explanation:

The amount of money Emma receives in this scenario is £35.
<h3>What is Ratio?</h3>
This is defined as a comparison of numbers that indicates their sizes in relation to each other.
Helen and Emma = 2 : 5
2 = 5
x = x+21
We then cross multiply
5x = 2 ( x+21)
5x = 2x + 42
5x - 2x = 42
3x = 42
x = 42/3 = 14
Emma received x+21
= 14+21 = £35
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8)
3x + 2 = 4x - 3
4x - 3x = 2 +3
x = 5
2y +7 = 4y - 9
4y - 2y = 7+9
2y = 16
y = 2
9)
2x - 2 = x + 2
2x - x = 2+2
x =4
5y - 8 = y+24
5y - y = 24 +8
4y = 32
y = 8