# Algebra Questions

• May 4th 2010, 09:30 PM
wheelsfire
Algebra Questions
Hi, i'm stuck on some questions that i need answered.

I have 3 questions i need help with.

I'm not sure where to start in order to answer the question.
I also have to show working.

What is a% of b% of c% of 1000 000?

Solve for x and y:

2x - 3y = 8 ....................(1)
5x + 2y = 31.4 ...............(2)

And

a) The store orders twice as many four burner BBQ’s as six burner BBQ’s. Each four burner BBQ is priced at $299 whilst each six burner BBQ is$450. The total bill for the order is $14 824 which includes a freight charge of$1 200.
Use algebra to determine the number of four burner and six burner BBQ’s ordered.
Let x = total of four burners, y = total of six burners
$14 824 = (x*299)+(y*450)+1200$13 624 = (x*299)+(y*450)
\$13 624 = 299x + 450y

• May 4th 2010, 09:33 PM
Anonymous1
Quote:

Originally Posted by wheelsfire

What is a% of b% of c% of 1000 000?
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$\frac{a}{100}\cdot \frac{b}{100}\cdot \frac{c}{100}\cdot 1,000,000 = a\cdot b \cdot c.$

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Solve for x and y:

2x - 3y = 8 ....................(1)
5x + 2y = 31.4 ...............(2)
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$\frac{2}{3}\cdot(1)$

$\Rightarrow \frac{4}{3}x - 2y = \frac{16}{3} \rightarrow (3)$

$(3) + (2)$

$\Rightarrow \frac{19}{3}x = \frac{551}{15}$

Now solve for $x$ and sub it back into $(2)$ to find y.

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aNon1
• May 4th 2010, 09:34 PM
pickslides
Quote:

Originally Posted by wheelsfire

Solve for x and y:

2x - 3y = 8 ....................(1)
5x + 2y = 31.4 ...............(2)

From (1) $2x - 3y = 8\implies 2x = 8+3y \implies x = 4+\frac{3y}{4}$

Now substitute this into (2) $5x + 2y = 31.4 \implies 5\left( 4+\frac{3y}{4}\right) + 2y = 31.4$

Now solve for $y$
• May 4th 2010, 10:54 PM
wheelsfire
who's answer is right? Anonmysus or pickslides?
• May 5th 2010, 04:40 AM
pickslides
Quote:

Originally Posted by wheelsfire
who's answer is right? Anonmysus or pickslides?

Two different methods. Mine is called 'substitution' method, Anon's is called the 'elimination' method, both will give you the correct answer. Your choice on which way to go.