Question

factorise by taking out common factor:
$6xy(a ^{2} + b {}^{2} ) + 8yz(a {}^{2} + b {}^{2} ) - 10xz(a {}^{2} + b {}^{2} )$

Answer 1

Your answer is here
$= (a {}^{2} + b {}^{2} )(6xy + 8yz) \\ = (a {}^{2} + b {}^{2} ) \: 2y(3x + 8z) \\ = 2y(a {}^{2} + b {}^{2} )(3x + 8z)$
I hope it helps you