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3 years ago

Solve the system for X: y=3x +4 у=х+8 x +10

Mathematics

1 answer:

Anastasy [175]3 years ago

3 0

Answer: The answers are x=y/3–4/3, and x=y/9–10/9.

Step-by-step explanation: You’ll need to isolate the variable by dividing each side by factors that don't contain the variable.

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A car covered a certain distance at a speed of 24 mph. While returning, the car covered the same distance at a speed of 16 mph.

igomit [66]

Since the distances were the same you can find the average speed directly by adding the speeds then dividing by 2. No need to weight anything.

If we’re considering speed regardless of direction, the average speed is:

(24 + 16) / 2 = 40 / 2 = 20mph

However if direction matters, then one number has to be negative since the directions are opposite:

(24 - 16) / 2 = 8 / 2 = 4mph (in the positive direction)

Depending on the context, either of these could be your answer.

7 0

3 years ago

Read 2 more answers

I really need help i’m going to fail so answer if you can ! <3

Volgvan

Answer:

110

Step-by-step explanation:

you place 30 in the place of X, and it becomes 4×30-10. in PEMDAS, multiplication goes first and 4×30=120. 120-10=110

8 0

3 years ago

Mr. Walker, a runner, asked students to find the unit rate of the winner of the first Boston Marathon in 1897. John J. McDermott

EleoNora [17]

Answer: 8.4 miles per hour

Step-by-step explanation:

Since, total distance = 24.5 miles,

Time taken = $175 \text{ minutes} = \frac{175}{60} \text{ hours} =\frac{35}{12} \text{ hours}$

Thus,

$\text{ The unit rate} = \frac{\text{ Total distance}}{\text{ Time taken}}$

$=\frac{24.5}{35/12}$

$=\frac{294}{35}$

$=8.4\text{ miles per hour}$

6 0

3 years ago

What is degenerate circle

Viefleur [7K]

It is the circle which has its radius a 0units and it can also be called as a point circle.

4 0

3 years ago

A rectangular swimming pool is bordered by a concrete patio. the width of the patio is the same on every side. the area of the s

andre [41]

Answer:

$x = \frac{1}{4}\left(-(l + w) + \sqrt{l^2 + 6lw + w^2} \right)$

where

l = length of the pool (w/o the patio)
w = width of the pool (w/o the patio)

Explanation:

Let

x = width of the patio
l = length of the pool (w/o the patio)
w = width of the pool (w/o the patio)

Since the pool is bordered by a complete patio,

Length of the pool (with the patio)
= (length of the pool (w/o the patio)) + 2*(width of the patio)
Length of the pool (with the patio) = l + 2x

Width of the pool (with the patio)
= (width of the pool (w/o the patio)) + 2*(width of the patio)
Width of the pool (with the patio) = w + 2x

Note that

Area of the pool (w/o the patio)
= (length of the pool (w/o the patio))(width of the pool (w/o the patio))
Area of the pool (w/o the patio) = lw

Area of the pool (with the patio)
= (length of the pool (w/o the patio))(width of the pool (w/o the patio))
= (l + 2x)(w + 2x)
= w(l + 2x) + 2x(l + 2x)
= lw + 2xw + 2xl + 4x²
Area of the pool (with the patio) = 4x² + 2x(l + w) + lw

Area of the patio
= (Area of the pool (with the patio)) - (Area of the pool (w/o the patio))
= (4x² + 2x(l + w) + lw) - lw
Area of the patio = 4x² + 2x(l + w)

Since the area of the patio is equal to the area of the surface of the pool, the area of the patio is equal to the area of the pool without the patio. In terms of the equation,

Area of the patio = Area of the pool (w/o the patio)
4x² + 2x(l + w) = lw
4x² + 2x(l + w) - lw = 0 (1)

Let

a = numerical coefficient of x² = 4
b = numerical coefficient of x = 2(l + w)
c = constant term = -lw

Then using quadratic formula, the roots of the equation 4x² + 2x(l + w) - lw = 0 is given by

$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
\\ = \frac{-2(l + w) \pm \sqrt{(2(l + w))^2 - 4(4)(-lw)}}{2(4)} 
\\ = \frac{-2(l + w) \pm \sqrt{(4(l + w)^2) + 16lw}}{8} 
\\ = \frac{-2(l + w) \pm \sqrt{(4(l^2 + 2lw + w^2) + 4(4lw)}}{8}
\\ = \frac{-2(l + w) \pm \sqrt{(4(l^2 + 2lw + w^2 + 4lw)}}{8}
\\ = \frac{-2(l + w) \pm \sqrt{(4(l^2 + 6lw + w^2)}}{8}$
$= \frac{-2(l + w) \pm 2\sqrt{l^2 + 6lw + w^2}}{8} \\= \frac{2}{8}(-(l + w) \pm \sqrt{l^2 + 6lw + w^2}) \\x = \frac{1}{4}(-(l + w) \pm \sqrt{l^2 + 6lw + w^2}) \\\boxed{x = \frac{1}{4}\left(-(l + w) + \sqrt{l^2 + 6lw + w^2} \right) \text{ or }}
\\\boxed{x = -\frac{1}{4}\left((l + w) + \sqrt{l^2 + 6lw + w^2} \right)}$

Since $(l + w) + \sqrt{l^2 + 6lw + w^2} \ \textgreater \ 0$ , $-\frac{1}{4}\left((l + w) + \sqrt{l^2 + 6lw + w^2}\right)$ is negative. Since x represents the patio width, x cannot be negative. Hence, the patio width is given by

$\boxed{x = \frac{1}{4}\left(-(l + w) + \sqrt{l^2 + 6lw + w^2} \right)}$

7 0

3 years ago