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3 years ago

X=3y+4 3x-5y=8 Solve using substitution

Mathematics

1 answer:

Mkey [24]3 years ago

4 0

x = 3y + 4

3x - 5y = 8

Because we have a value for x, we can plug it into the second equation to solve for y.

3(3y + 4) - 5y = 8

9y + 12 - 5y =8

Combine like terms.

4y + 12 = 8

Subtract 12 from both sides.

4y = -4

Divide both sides by 4.

y = -1

Because we have a constant value for y, we can solve for x.

x = 3(-1) + 4

x = -3 + 4

x = 1

<h3>The value of x is equal to 1.</h3><h3>The value of y is equal to -1.</h3>

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Car X and car Y traveled the same 80-mile route. If car X took 2 hours and car Y traveled at an average speed that was 50 percen

KiRa [710]

Answer:

Step-by-step explanation:

Both cars, X and Y travelled 80 miles each.

Speed = distance/time

If car X took 2 hours to travel 80 miles, it means that the speed at which car X travelled is

80/2 = 40 mph

If car Y traveled at an average speed that was 50 percent faster than the average speed of car X, it means that the speed at which car X travelled is

40 + 0.5 × 40 = 60 mph

Time = distance/speed

Therefore, time taken by car Y to travel 80 miles is

80/60 = 1.33 hours

7 0

3 years ago

A triangle has side lengths of (8d – 3) centimeters, (6d + 2) centimeters, and

alisha [4.7K]

The perimeter of a triangle is the sum of its side lengths.

The perimeter of the triangle is: $14d + 7f +7$

<u>The sides of the triangle are:</u>

Side 1 = (8d - 3) cm

Side 2 = (6d + 2) cm

Side 3 = (7f + 8) cm

The perimeter (P) is calculated as:

P = Side 1 + Side 2 + Side 3

So, we have:

$P = (8d - 3) + (6d + 2) + (7f + 8)$

Remove brackets

$P = 8d - 3 + 6d + 2 + 7f + 8$

Collect like terms

$P = 8d + 6d + 7f - 3 + 2 + 8$

$P = 14d + 7f +7$

Hence, the perimeter of the triangle is: $14d + 7f +7$

Read more about perimeters at:

brainly.com/question/6465134

3 0

3 years ago

What is the completely factored form of d4 − 81?

lilavasa [31]

For this case we must factor the following expression:

$d ^ 4-81$

Rewriting the expression:

$(d ^ 2) ^ 2-9 ^ 2$

We factor using the formula of the square difference:

$a ^ 2-b ^ 2 = (a + b) (a-b)$

Where:

$a = d ^ 2\\b = 9$

So:

$(d ^ 2 + 9) (d ^ 2-9)$

From the second term we have:

$d ^ 2-3 ^ 2 = (d-3) (d + 3)$

Finally, the factored expression is:

$(d ^ 2 + 9) (d-3) (d + 3)$

Answer:

$(d ^ 2 + 9) (d-3) (d + 3)$

4 0

3 years ago

Read 2 more answers

i When 20 is added to a certain number and the sun is divided by 3, the result is 3 times the number, find the number.

Bingel [31]

Answer:

$let \: the \: number \: be \: x \\ \frac{20 + x}{3} = 3x \\ \frac{3(20 + x)}{3} = (3x)3 \\ 20 + x = 9x \\ 20 = 9x - x \\ 20 = 8x \\ \frac{20}{8} = \frac{8x}{8} \\ x = 2.5$

Step-by-step explanation:

Hope that this is helpful .

Have a great day.

3 0

3 years ago

3. Suppose the mystery bag had resulted in the following number of red chips. Using the simulated sampling distributions found e

Vinvika [58]

Answer:

a) 0.172

b) 0.167

c) 0.1404

Step-by-step explanation:

Margin of error, E = $2\times\sqrt{\frac{p(1-p)}{n}}$

here,

p = probability of the event

n = sample size

a) n = 30

p = 10 ÷ 30 = 0.333

Therefore,

E = $2\times\sqrt{\frac{0.333(1-0.333)}{30}}$

= 2 × 0.0861

= 0.172

b) n = 30

p = 21 ÷ 30 = 0.7

Therefore,

E = $2\times\sqrt{\frac{0.7(1-0.7)}{30}}$

= 2 × 0.0836

= 0.167

c) n = 30

p = 22 ÷ 50 = 0.44

Therefore,

E = $2\times\sqrt{\frac{0.44(1-0.44)}{50}}$

= 2 × 0.0702

= 0.1404

3 0

3 years ago