Question 182308
Let {{{p}}}= number Paul sold
Let {{{j}}}= number John sold
given:
(1) {{{p + j = 41}}}
(2) {{{p = j + 9}}}
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Substitute (2) in (1)
(1) {{{p + j = 41}}}
{{{j + 9 + j = 41}}}
{{{2j = 32}}}
{{{j = 16}}}
John sold 16 CDs
check:
(2) {{{p = j + 9}}}
{{{p = 16 + 9}}}
{{{p = 25}}}
(1) {{{p + j = 41}}}
{{{25 + 16 = 41}}}
{{{41 = 41}}}
OK