-10.3 + y = 5.2
First, regroup the terms. / Your problem should look like:
Second, add 10.3 to both sides. / Your problem should look like:
Third, add 5.2 + 10.3 to get 15.5 / Your problem should look like:

Answer:
y = 15.5 (D)
Answer:
Height of the goalpost is 9.25 m.
Step-by-step explanation:
As per the rule of reflection in physics,
Angle of incidence = Angle of reflection
As we can see in the picture attached, both the angles (θ) are equal.
m∠ACB = m∠ECD = 90° - θ
m∠ABC = m∠ADC = 90°
Therefore, both the triangles ΔABC and ΔEDC will be similar.
And by the property of similar triangles, their corresponding sides will be proportional.


ED = 
ED = 9.25 m
Height of the goalpost is 9.25 m.
Switch sides
4/5 (x+3)=y+6
Multiply both sides by 5
5*4/5 (x+3) = 5y+5*6
Simplify
4(x+3) = 57+30
Divide both sides by 4
4(x+3)/4 = 5y/4+ 30/4
Simplify
x+3 = 5y+30/4
Subtract 3 from both sides
x+3 - 3 = 5y+30/4 - 3
Simplify
x=5y+30/4 - 3
Help the math of mine plz