Question 134468
{{{x}}} = amount invested at 12%
{{{y}}} = amount invested at 10%
{{{.12x + .1y = 890}}}
{{{x + y = 7500}}}
{{{x = 7500 - y}}}
{{{.12*(7500 - y) + .1y = 890}}}
{{{900 - .12y + .1y = 890}}}
{{{-.02y = -10}}}
{{{y = 10/.02}}}
{{{y = 1000/2}}}
{{{y = 500}}}
{{{x = 7500 - y}}}
{{{x = 7000}}}
He invested $7000 at 12%
check:
{{{.12*(7500 - y) + .1y = 890}}}
{{{.12*(7500 - 500) + .1*500 = 890}}}
{{{.12*7000 + 50 = 890}}}
{{{840 + 50 = 890}}}
{{{890 = 890}}}
OK