Given a + B = 2, then the value of a & # 178; + 4b-b & # 178; is ()

Given a + B = 2, then the value of a & # 178; + 4b-b & # 178; is ()

a²+4b-b² = a²-b²+4b = （a+b）(a-b)+4b = 2(a-b)+4b = 2(a+b) = 4

A & # 178; + B & # 178; - A + 4B + 4.5 = 0 find the value of ab

The original formula can be changed into
(a -- 0.5) ^ 2 + (B + 2) ^ 2 = -- 0.25 (negative 025)
This equation has no real solution and the sum of squares is not negative
If 4.5 is changed to 4.25, there is a solution

If a & # 178; + B & # 178; - 2a-4b + 5 = 0, find the value of a ^ b-ab

∵ A & # 178; + B & # 178; - 2a-4b + 5 = 0 ∵ (A & # 178; - 2A + 1) + (B & # 178; - 4B + 4) = 0 ∵ A-1 & # 178; + (b-2) & # 178; = 0 ∵ A-1 = 0, B-2 = 0 ∵ a = 1, B = 2 ∵ a ^ b-ab = 1 &