Question

plzz solve these three questions and give me answer fastly it is very urgent

Answer 1

$(13) \: \: on \: dividing \: 9x {}^{4} - 4 {}^{2} + 5 \: by \: 3x {}^{2} + x - 1 \: we \: get \: remainder \: - x + 5$
$but \: given \: remainder \: is \: ax - b$
$so \: compairing \: these$
we get
$a = - 1 \\ \\ b = - 5$