Question 565075
Let {{{ p }}} = pounds of peanuts he ordered
Let {{{ c }}} = pounds of cashews he ordered
given:
(1) {{{ p + c = 70 }}}
(2) {{{ c = p - 20 }}}
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Substitute (2) into (1)
(1) {{{ p + p -20 = 70 }}}
(1) {{{ 2p = 70 + 20 }}}
(1) {{{ 2p = 90 }}}
(1) {{{ p = 45 }}}
He ordered 45 pounds of peanuts
check:
(2) {{{ c = 45 - 20 }}}
(2) {{{ c = 25 }}}
and
(1) {{{ 45 + 25 = 70 }}}
(1) {{{ 70 = 70 }}}
OK