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3 years ago

Solving systems by elimination 9x+3y=-3 2x-3y=-8

Mathematics

1 answer:

Alona [7]3 years ago

5 0

Answer:

Solve for the first variable in one of the equations, then substitute the result into the other equation.

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Step-by-step explanation:

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Si a los lados de un cuadrado se le aumenta en 3 y 5 m respectivamente la superficie del nuevo rectangulo es 440m .Encontrar el

Ivahew [28]

Answer:

El lado del cuadrado inicial es 17 m.

Step-by-step explanation:

El área de un rectángulo se calcula a partir de los dos lados diferentes. Siendo a y b el valor de ambos lados, el área de la figura es el producto de los dos lados contiguos del rectángulo.

A los lados de un cuadrado se le aumenta en 3 y 5 m respectivamente la superficie del nuevo rectángulo es 440 m². Siendo x el lado del cuadrado inicial, entonces el área del rectángulo se puede expresar como:

(x+3)*(x+5)= 440 m²

Resolviendo:

x*x + 5*x + 3*X + 3*5= 440

x² + 8*x + 15=440

x² + 8*x + 15 -440= 0

x² + 8*x -425= 0

Una función cuadrática de la forma a*x² + b*x + c= 0 se puede resolver mediante la expresión:

$\frac{-b+-\sqrt{b^{2}-4*a*c } }{2*a}$

En este caso, a=1, b=8 y c=425. Reemplazando:

$\frac{-8+-\sqrt{8^{2}-4*1*(-425) } }{2*1}$

Resolviendo:

$\frac{-8+\sqrt{8^{2}-4*1*(-425) } }{2*1}= \frac{-8+\sqrt{64+1700} }{2*1}= \frac{-8+\sqrt{1764 } }{2}= \frac{-8+42 }{2}= \frac{34}{2} = 17$

$\frac{-8-\sqrt{8^{2}-4*1*(-425) } }{2*1}= \frac{-8-\sqrt{64+1700} }{2*1}= \frac{-8-\sqrt{1764 } }{2}= \frac{-8-42 }{2}= \frac{-50}{2} = -25$

Como las longitudes no pueden ser negativas, el lado del cuadrado inicial es 17 m.

3 0

2 years ago

Cathie is making a dress with a sash. The sash needs to be 72.1 inches long, but Cathie's measuring tape is only in centimeters.

sveta [45]

183.134cm is the answer

8 0

2 years ago

HELPPPPP !!!!! Answers ????

tamaranim1 [39]

All 3 sides are all equal

7 0

3 years ago

Read 2 more answers

A farmer randomly inspected 16 of his 93 peach trees for signs of disease. Two of those trees showed signs of disease. Find .

Dmitriy789 [7]

I think you wanted to find p̂, or "p-hat". This is simply the proportion of the sample. So:

p̂ = 16/93 ~= 0.172

Hope this helps :)

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2 years ago

Read 2 more answers

Need help asap important! thanks so much!

a_sh-v [17]

Answer:

You would have $343.37 at the end of the 2 years.

Step-by-step explanation:

Interest earned is like bonus money the bank pays you just for keeping money

$\mathrm{Compund\:Interest\:Formula}:\quad A = P { \left( 1+ \dfrac{ r }{ n } \right) }^{ nt }$

P: the starting balance of the account (also called initial deposit, or principal)

A: the new balance in the account after N years.

t: the number of years or time

r: the interest rate, (in decimal form)

n: the number of times the interest is compounded each year.

Annually = each year = 1

P =$300, r = 7%, t = 2, n = 1, A = ?

Substitute the numbers into the "Compound Interest Formula".

$A = 300 { \left( 1+ \dfrac{ 0.07 }{ 1 } \right) }^{ 1 \times 2 }$

$\mathrm{Anything\:divided\:by\:1\:gives\:itself}$

$A = 300 { \left( 1+0.07 \right) }^{ 1 \times 2 }$

$\mathrm{Add\:1\:and\:0.07\:to\:get\:1.07}$

$A = 300 \times { 1.07 }^{ 1 \times 2 }$

$\mathrm{Multiply\:1\:and\:2\:to\:get\:2}$

$A = 300 \times { 1.07 }^{ 2 }$

$\mathrm{Calculate\:1.07\:to\:the\:power\:of\:2\:and\:get\:1.1449}$

$A = 300 \times 1.1449$

$\mathrm{Multiply\:300\:and\:1.1449\:to\:get\:343.47}$

$A = 343.47$

So you would have $343.37 at the end of the 2 years.

Look at the chart

$\mathrm{Year}\quad \mathrm{Year\: Interest}\quad \mathrm{Total\:Interest}\quad \mathrm{Balance}\\\quad1\quad\quad\quad $21.00\quad\quad\quad\quad $21.00\quad\quad\quad\quad $321.00\\\quad2\quad\quad\quad $22.47\quad\quad\quad\quad $43.47\quad\quad\quad\quad $343.47$

8 0

2 years ago