Question 163036
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Remember the following,
Number of Pencils={{{x}}}
Number of Pens={{{y}}}
So, {{{x+y=17}}} right? -----------------------------> EQN 1
In EQN 1 ,we also get,
{{{x=17-y}}} ----------------------------------------> EQN 2
Next, we know the cost for each pencil & Pen with a total cost of $5.00, so
{{{0.50x+0.25y=5.00}}} ------------------------------> EQN 3
Subst. EQN 2 in EQN 3,
{{{0.50(17-y)+0.25y=5.00}}}
{{{8.5-0.50y+0.25y=5.00}}}
{{{8.5-5.00=0.50y.25y}}}
{{{3.50=0.25y}}} --------> {{{cross(3.50)14/cross(.25)=cross(0.25)y/cross(0.25)}}}
{{{highlight(y=14)}}}, Number of Pens
Via EQN 2, {{{highlight(x=17-14=3)}}}, Number of Pencils
In doubt? Go back EQN 3,
{{{0.50(3)+0.25(14)=5.00}}}
{{{1.50+3.50=5.00}}}
{{{5.00=5.00}}}
Thank you,
Jojo</pre>