does anyone know the answer???

Answer:a = √5 b ∈ (−∞,∞)Step-by-step explanation:(7 + 3√5)/(3 + √5) - (7 - 3√5)/(3 - √5) = a + b√5⇔ (7 + 3√5)(3 - √5)/(3 + √5)(3 -√5) - (7 - 3√5)(3 + √5)/(3 + √5)(3 -√5) = a + b√5 ⇔ (7 + 3√5)(3 - √5) -  (7 - 3√5)(3 + √5)/(3 + √5)(3 -√5) = a + b√5⇔ 4√5/4 = a + b√5⇔ √5 = a + b√5 ⇔ b = (5 - a√5)/5 Replace b with (5 - a√5)/5 ⇒ a +  (5 - a√5)/5 = √5⇔ a × 5 + (5 - a√5)(5)/5 = √5 × 5⇔ a × 5 + 5 - a√5 = 5√5 ⇔ a × 5 - √5 × a = 5√5 - 5⇔ a(5 - √5) = 5√5 - 5⇔ a = √5