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3 years ago

Solve by using substitution-7x-2y=-13 and x-2y=11

1 answer:

7 0

$\left \{ {{-7x-2y=-13} \atop {x-2y=11}} \right. \\\\ \left \{ {{-7x-2y=-13} \atop {x=11+2y}} \right.\\\\
Substitute\ second\ equation\ into\ the\ first\ one:\\\\
-7(11+2y)-2y=-13\\
-77-14y-2y=-13\\
-77-16y=-13\ \ \ |Add\ 77\\
-16y= 64\ \ \ |Divide\ by\ -16\\
y=-4\\\\x=11+2y=11+2*(-4)=11-8=3\\\\ \left \{ {{y=-4} \atop {x=3}} \right.$

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Brrunno [24]

The number is -6.67

<em><u>Solution:</u></em>

Let "n" be the number

From given,

$\text{ Five less than 1/5 times a number } = \frac{1}{5}n - 5 = \frac{5}{n} - 5$

$\text{Sum of number and 1/3 } = n + \frac{1}{3} =\frac{3n+1}{3}$

Given that,

Five less than 1/5 times a number is the same as the sum of the number and 1/3

Therefore, we get,

$\frac{n}{5} - 5 = n + \frac{1}{3}\\\\Simplify\ the\ expression\\\\n - 25 = 5(n + \frac{1}{3})\\\\n - 25 = 5n + \frac{5}{3}\\\\n - 25 = \frac{15n + 5}{3}\\\\3n - 75 = 15n + 5\\\\12n = -80\\\\n = -6.67$

Thus the number is -6.67

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3 years ago

richard spends 30% of his monthly budget on rent. His total monthly is 3,000. How much does Ricard spend on rent

Alexeev081 [22]

He spends 900 on rent

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3 years ago

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Stefan sells Jin a bicycle for $138 and a helmet for $18. The total cost for Jin is 130% of what

lys-0071 [83]

Answer:

1. $109.20 2. $46.80

Step-by-step explanation:

Doing the math, we find that 30% of 156 (138+18) is 46.80, which answers the second part of this problem. Plugging this value into the first part of the equation gives us what Stefan originally paid.

Good luck! Hope this helps!

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2 years ago

Find x of the triangle

sukhopar [10]

Answer:

Step-by-step explanation:

altitude = sqrt(6*8) = 4*sqrt(3)

Use the Pythagorean Theorem to derive x

altitude^2 + 18^2 = x^2

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3 years ago

The graph below shows the amount of money left in the school’s desk fund, f, after d desks have been purchased. A graph titled D

natima [27]

Answer:

$110

Step-by-step explanation:

The computation is shown below:

Provided that

Number of desk purchased Fund Left $

0 700

1 590

2 480

3 370

4 260

5 150

6 40

Now the Fund decreased while purchasing is

= 5 desks - 2 desks

= 3 desks

i.e

= $480 - $150

= $330

Now the amount of money left for decreased the desk fund is

$= \frac{Fund\ decreased }{number\ of\ desk\ decreased}$

$= \frac{\$330}{3\ desk}$

= $110

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3 years ago

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