Question

已知4a的平方+b的平方-4a+6b+10=0,求(4a-3b)的平方

Answer 1

4a^2+b^2-4a+6b+10=0

4a^2-4a+1+b^2+6b+9=0

(2a-1)^2+(b+3)^2=0

2a-1=0 b+3=0

a=1/2 b=-3

(4a-3b)^2

=(4*1/2-3*(-3))^2

=(2+9)^2

=11^2

=121