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4 years ago

The length of a rectangle is 8 feet more than it’s worth. The area of the rectangle is 84 ft.². Find its Length and width.

Mathematics

1 answer:

Furkat [3]4 years ago

5 0

Answer: 100 i think, but am not sure.

Step-by-step explanation:

The formula for area of a rectangle is A=l*w. Since the area is 84, then you can use the A=l*w formula. 84 = x(x+8) would be the equation to solve for x.

Now, you need to put the equation in standard form. So, x2 + 8x - 84 = 0.

Since you can't solve this quadratic using factoring, you need to complete the square.

To complete the square you need to add 84 to both sides. Now you have x2 + 8x = 84. Take the coefficient for the x term (8) and divide by 2. Now square it. That would be 42, so 16. Now you have x2 +8x +16 = 100.

Factor x2 +8x +16, so (x+4)2 = 100

If you use the square root property, you have x+4 = 10. Therefore, x = 6 (the short side) and 14 is the long side.

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HELP PLEASE ASAP

olga2289 [7]

Answer: a) degree and sign

b) end behavior: left side → +∞, right side → -∞

c) x-intercepts: x = -1.3, 0.3, 1.0

<u>Step-by-step explanation:</u>

end behavior can be determined by two things:

1) the degree of the polynomial:

if the degree is an even number, then the end behavior will be the same for both the left and right sides.
if the degree is an odd number, then the end behavior will be different for both the left and right sides.

2) the sign of the leading coefficient:

If the leading coefficient is positive, then the end behavior of the right side goes to positive infinity
If the leading coefficient is negative, then the end behavior of the right side goes to negative infinity

W(x) = -5x³ + 7x - 2

Degree: 3 (odd)

Leading Coefficient: negative

So, end behavior is: right side goes to negative infinity, right side goes to positive infinity.

See attachment for x-intercepts. <em>I set the x-axis to represent tenths </em>

5 0

3 years ago

What is the value of x in a 45-45-90 triangle and the hypotenuse is 4?

Temka [501]

9514 1404 393

Answer:

x = 2√2 ≈ 2.83

Step-by-step explanation:

The side length of an isosceles right triangle is 1/√2 times the hypotenuse length. If x is the side length, then ...

x = 4/√2 = 4(√2)/2

x = 2√2 ≈ 2.83

You have not specified the form of the answer. Sometimes an exact answer (2√2) is required. Sometimes the answer is required to be rounded to tenths or hundredths.

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3 years ago

How to solve 4y=x 3x- y=70 using substitution

creativ13 [48]

X = 4y
3x - y = 70

substitute the x in the second equation with the other half of the first equation.

3(4y) - y = 70
12y - y = 70
11y = 70
y = 6.36 repeating, or 6 4/11

now use this to solve first equation
x = 4 (6 4/11)
x = 25.45 repeating

done

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3 years ago

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zysi [14]

A I think I’m not really sure

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3 years ago

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madreJ [45]

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