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nekit [7.7K]
3 years ago
5

Solve the following system of equations by elimination. Express

Mathematics
1 answer:
Greeley [361]3 years ago
4 0
Add the two equations together with the same variables

-x+4x=3x
-3y+3y=0
20+1=21

You now get

3x=21

Divide and find x =7

Plug in x to the equation to find y
Y=-9

(7,-9)
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Jose bought 750 bags of peanuts for 375.00. He intends to sell each bag for 0.15 more the he paid. How much should he charge for
pantera1 [17]
Find out how much is 1 bag of peanuts that he bought.

375.00 divided by 750 = 0.50 cents

0.50 + 0.15 = 0.65 cents

Jose should charge 0.65 cents for each bag.
4 0
2 years ago
Read 2 more answers
Wich equation best represent the relation ship between x and y plz answer
Llana [10]

Answer:

.

Step-by-step explanation:

6 0
3 years ago
A fossil was analyzed and determined to have a carbon-14 level that is 80 % that of living organisms. the half-life of c-14 is 5
liq [111]

Answer:

The fossil is 1860 years old.

Step-by-step explanation:

The equation for the amount of fossil has the following format:

Q(t) = Q(0)e^{rt}

In which Q(t) is the amount after t years, Q(0) is the initial amount and r is the rate of change.

Half-life of c-14 is 5730 years.

This means that Q(5730) = 0.5Q(0)

So

Q(t) = Q(0)e^{rt}

0.5Q(0) = Q(0)e^{5730r}

e^{5730r} = 0.5

\ln{e^{5730r}} = \ln{0.5}

5730r = \ln{0.5}

r = \frac{\ln{0.5}}{5730}

r = -0.00012

So

Q(t) = Q(0)e^{-0.00012t}

How old is the fossil?

This is t for which

Q(t) = 0.8Q(0)

So

Q(t) = Q(0)e^{-0.00012t}

0.8Q(0) = Q(0)e^{-0.00012t}

e^{-0.00012t} = 0.8

\ln{e^{-0.00012t}} = \ln{0.8}

-0.00012t = \ln{0.8}

t = -\frac{\ln{0.8}}{-0.00012}

t = 1860

The fossil is 1860 years old.

4 0
3 years ago
Para recortar algumas figuras geométricas, um aluno utilizou uma cartolina com 1mx0,8m. Sabendo que ele recortou 2 triângulos, a
Gnom [1K]

Answer:

7190 cm²

Step-by-step explanation:

Para recortar algumas figuras geométricas, um aluno utilizou uma cartolina de 1 m x 0,8m.

Passo 1

Determine a área de todo o papelão

= Temos dimensões = 1mx0,8m

Área = Comprimento × Largura

= 0,8m²

Nós convertemos para cm²

1 m² = 10.000 cm²

0,8m² = x cm²

Multiplicação cruzada

0,8m² × 10.000 cm² / 1 m²

= 8000 cm²

Passo 2

Sabendo que recortou 2 triângulos, ambos com 20cm de base e 30cm de altura

Encontramos a área de um triângulo

= 1/2 × base × altura

= 1/2 × 20 × 30

= 300cm²

Ele cortou 2 triângulos Portanto, o são dos dois triângulos = 300cm² × 2

= 600cm²

etapa 3

Ele também cortou 2 trapézios ambos com bases de 10cm e 20cm e altura de 7cm.

A área de um trapézio =

1/2 (a + b) h

= 1/2 (10cm + 20cm) × 7cm

= 1/2 × 30 × 7

= 105 cm²

Ele cortou dois trapézios, portanto

A área dos dois trapézios do corte = 105cm² × 2

= 210 cm²

Passo 4

A área total do papelão que foi cortado = 600cm² + 210cm²

= 810 cm²

Etapa 5

Determine em cm² quanto de papelão sobrou.

Isso é calculado como:

Área total do papelão - Área total que foi cortada

= 8000 cm² - 810 cm²

= 7190 cm²

5 0
3 years ago
Can you please help thanks
katrin2010 [14]

Answer:5/2a + 10/3b

Step-by-step explanation:

(1/6)(15a+20b)

=(1/6)(15a)+(1/6)(20b)

6 0
3 years ago
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