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2 years ago

Solve 3x+2y=7 and x-4y=-21 by using substitution

1 answer:

7 0

$3x+2y=7 \\
x-4y=-21 \\ \\
\hbox{solve the second equation for x:} \\
x-4y=-21 \\
x=4y-21 \\ \\
\hbox{substitute 4y-21 for x in the first equation:} \\
3(4y-21)+2y=7 \\
12y-63+2y=7 \\
14y=7+63 \\
14y=70 \\
y=\frac{70}{14} \\
y=5 \\ \\
x=4y-21=4 \times 5-21=20-21=-1 \\ \\
\boxed{(x,y)=(-1,5)}$

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2 years ago

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3 years ago

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3 years ago

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3 years ago

There are 486 hamsters at a private showing of a new documentary about humans. If there are 12 seats in each row, about how many

Citrus2011 [14]

Answer:

40 rows will hamsters fill

Step-by-step explanation:

As per the statement:

There are 486 hamsters at a private showing of a new documentary about humans.

⇒Total number of hamsters = 486

It is also given that there are 12 seats in each row.

then;

They will fill = $\frac{486}{12} = 40.5$

Therefore, the best estimate the rows will hamsters fill is 40 rows.

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3 years ago