Question 73376
{{{sqrt(63) - 2sqrt(28) + 5sqrt(7)}}}
= {{{sqrt(9*7) - 2sqrt(4*7) + 5sqrt(7)}}}
= {{{sqrt(9)*sqrt(7) - 2sqrt(4)*sqrt(7) + 5sqrt(7)}}}
= {{{3sqrt(7) - 2*2*sqrt(7) + 5sqrt(7)}}}
= {{{3sqrt(7) - 4sqrt(7) + 5sqrt(7)}}}
= {{{sqrt(7)(3 - 4 + 5)}}}
= {{{sqrt(7)*4}}}
= {{{4sqrt(7)}}}