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2 years ago

Use method of subtitution, will give brainliest, 20 pts

Mathematics

2 answers:

Anni [7]2 years ago

7 0

The answer is x = 3, y = -2 or (3, -2).

We are given that :

<u>2x + 5y = -4</u>
<u>y = x - 5</u>

Let us substitute the 2nd equation's value of y in the 1st equation.

2x + 5(x - 5) = -4
2x + 5x - 25 = -4
7x = 21
x = 3

Now, substitute for x in the 2nd equation.

y = 3 - 5
y = -2

Kitty [74]2 years ago

5 0

Answer:

x=3

y = -2

Step-by-step explanation:

2x+5y = -4

y = x-5

We want to use substitution

In the first equation, every time we see y, substitute x-5

2x + 5( x-5) = -4

Distribute

2x + 5x -25 = -4

Combine like terms

7x -25 = -4

Add 25 to each side

7x -25+25 = -5+25

7x = 21

Divide each side by 7

7x/7 = 21/7

x=3

Now we can find y

y = x-5

y = 3-5

y = -2

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6 0

3 years ago

Read 2 more answers

You have two circles, one with radius r and the other with radius R. You wish for the difference in the areas of these two circl

gtnhenbr [62]

Answer:

maximum difference of radii = $(r-R)=\frac{1}{2\pi ^{2}}$

Step-by-step explanation:

We know that area of circle is given by

$A=\pi \times (radius)^{2}$

For circle with radius 'r' we have

$A_{1}=\pi \times (r)^{2}$

For circle with radius 'R' we have

$A_{2}=\pi \times (R)^{2}$

Now according to given condition we have

$A_{1}-A_{2}\leq \frac{5}{\pi }$

$\Rightarrow \pi r^{2}-\pi R^{2}\leq \frac{5}{\pi }\\\\\Rightarrow (r^{2}-R^{2})\leq \frac{5}{\pi ^{2}}\\\\(r+R)(r-R)\leq \frac{5}{\pi ^{2}}\\\\\because (a^{2}-b^{2})=(a+b)(a-b)\\\\(r+R)=10(Given)\\\\\Rightarrow(r-R)\leq \frac{5}{10\pi ^{2}}\\\\\therefore (r-R)\leq\frac{1}{2\pi ^{2}}$

Thus maximum difference of radii = $(r-R)=\frac{1}{2\pi ^{2}}$

6 0

4 years ago

Kevin delivers newspapers in his town every morning. The amount he earns from delivering newspapers is given by y = 30x + 18, wh

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Y=30x+18
well if he didn't deliver to any houses he would be paid 18$.

8 0

3 years ago

The radius of a sphere is 7 meters what is the circle's area

Pie

★ Given :

$\begin{lgathered}\bullet\:\:\textsf{Radius of circle = \textbf{7 meter}}\end{lgathered}$

$\rule{130}1$

★ Digram :

$\setlength{\unitlength}{1mm}\begin{picture}(50,55)\thicklines\qbezier(25.000,10.000)(33.284,10.000)(39.142,15.858)\qbezier(39.142,15.858)(45.000,21.716)(45.000,30.000)\qbezier(45.000,30.000)(45.000,38.284)(39.142,44.142)\qbezier(39.142,44.142)(33.284,50.000)(25.000,50.000)\qbezier(25.000,50.000)(16.716,50.000)(10.858,44.142)\qbezier(10.858,44.142)( 5.000,38.284)( 5.000,30.000)\qbezier( 5.000,30.000)( 5.000,21.716)(10.858,15.858)\qbezier(10.858,15.858)(16.716,10.000)(25.000,10.000)\put(25,30){\line(5,0){20}}\put(25,30){\circle*{1}}\put(29,26){\sf\large{7 m}}\end{picture}$

$\rule{130}1$

★ Solution :

☯ $\underline{\boldsymbol{According\: to \:the\: Question\:now :}}$

$:\implies\sf Area\:of\:circle = \pi r^2 \\\\\\:\implies\sf Area\:of\:circle = \dfrac{22}{\cancel{7}} \times \cancel{7} \times 7\\\\\\:\implies\sf Area\:of\:circle = 22 \times 7\\\\\\:\implies\sf Area\:of\:circle = 154 m^{2}$