Help, Answer ASAP; will give brainliest

Answer:
a = 2, b = 3
Step-by-step explanation:
The diagonals of a rectangle bisect each other, thus
5a² = 4a² + 4 ( subtract 4a² from both sides )
a² = 4 ( take the square root of both sides )
a = [tex]\sqrt{4}[/tex] = 2
Also
6b - 8 = 4b - 2 ( subtract 4b from both sides )
2b - 8 = - 2 ( add 8 to both sides )
2b = 6 ( divide both sides by 2 )
b = 3