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3 years ago

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For $7.52, you purchased 8 pens and highlighters from a local bookstore. Each highlighter costs $1.09 and each pen costs $.69. H

ow many pens did you buy?

1 answer:

neonofarm [45]3 years ago

7 0

P=number of pens
h=number of highlighters

p+h=8

1.09h+0.69p=752

p+h=8
minus h from both sides
p=8-h

sub that for p

1.09h+0.69(8-h)=7.52
1.09h+5.52-0.69h=7.52
0.4h+5.52=7.52
minus 5.52 from both sides
0.4h=2
divide both sides by 0.4
h=5

sub back

h=8-p
5=8-p
minus 8 frm both sides
-3=-p
mltiply both sides by -1
3=p

3 pens you bought

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Please solve this for me using substitution

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<h2> <u>Explanation</u><u>:</u></h2>

$\bf \underline{★Given-} \\$

$\textsf{4x + 5y = 8};$

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$\bf \underline{★To\: find-} \\$

$\textsf{the value of x and y in equation?}$

$\bf \underline{★Solution-} \\$

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$\sf \leadsto 5x + 4y = 12 - - - (ii)$

By first equation,

$\sf \leadsto 4x + 5y = 8$

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