Question 188298
<font face="Tahoma" size=1.5>
</pre><font size=4><b>
Let <font color=blue>x</font> = money invested money that made 8% profit


Then, <font color=blue>$20,000 - x </font> = money invested at 7% profit


Also, let <font color=brown>y</font> = profit for 7% bonds


Then again, <font color=brown> $700 + y </font> = profit for 8%, $700 more than profit on 7%.


Putting into eqn for 8%:
{{{0.08(x)=700+y}}} --------------------> Eqn 1


Putting into eqn for 7%:
{{{(20000-x)(0.07)=y}}} ----------------> Eqn 2


In Eqn 1 we get, {{{y=0.08(x)-700}}} -----> Eqn 3, substitute in Eqn 2:


{{{(2000-x)(0.07)=highlight((0.08)(x)-700)}}}
{{{1400-0.07x=0.08x-700}}}
{{{1400+700=0.08x+0.07x}}}
{{{2100=0.15x}}}------> {{{cross(2100)14000/cross(0.15)=cross(0.15)x/cross(0.15)}}}


<font color=blue>x = $14,000 </font> money invested for 8%


$20,000 - $14,000 = <font color=red>$6,000 </font> money invested for 7%.( Answer)


Let's check the Profit


For 7%
$6000 x 0.07 = <font color=blue> $420 </font>


For 8%
$14,000 x 0.08 = <font color=blue> $1120 </font>


Profit (8%) - Profit (7%) = $1120 - $420 = <font color=brown> $700 </font>
That is right, $700 more on 8%.


Thank you,
Jojo</font>