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4 years ago

9x+7 when x+3 and x4 when x =3 pls do step by step

Mathematics

2 answers:

Anastaziya [24]4 years ago

6 0

Answer:

x=1

Step-by-step explanation: 9x+7=16

Subtract 7 from both sides.

9x=16−7

Subtract 7 from 16 to get 9.

9x=9

Divide both sides by 9.

Divide 9 by 9 to get 1.

x=1

sergiy2304 [10]4 years ago

3 0

Answer:

Step-by-step explanation:

9x+7 when x=3

Plug 3 into the equation for the variable x

So, it would be 9(3)+7

Multiply 9×3 together to get 27

Finally, add 27 and 7 together

The answer should be 34

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What type(s) of symmetry does the figure have? (Check all that apply.)

monitta

2 Answers: A) line symmetry and B) rotational symmetry

=====================================================

Explanation:

We have line symmetry because we can draw a vertical line down the center, and this is a mirror line. One half folds over the vertical line to match up with the other half. There are other lines of symmetry as well.

We also have rotational symmetry because we can rotate the figure some amount of degrees and have it line up with its original image. The before and after will be identical. This applies to any regular polygon.

8 0

3 years ago

A 20-ft by the 40-ft rectangular swimming pool is surrounded by a walkway of uniform width. If the total area of the walkway i

Jlenok [28]

<h3>Answer: 2 feet</h3>

========================================================

Explanation:

x = width of the walkway in feet

This is some positive real number.

The dimension of 20 feet bumps up to 20+2x when adding on x from both directions. Similarly, the 40 ft dimension becomes 40+2x

Refer to the diagram below.

The 20 ft by 40 ft pool is surrounded by a larger rectangle that is 20+2x ft by 40+2x ft

The pool itself is 20*40 = 800 sq ft. Add on the walkway area to get 800+256 = 1056 sq ft.

-----------

Area = length*width

1056 = (20+2x)*(40+2x)

1056 = 20*40 + 20*2x + 2x*40 + 2x*2x ... FOIL rule

1056 = 800 + 40x + 80x + 4x^2

0 = 4x^2 + 40x + 80x + 800 - 1056

0 = 4x^2 + 120x - 256

4x^2 + 120x - 256 = 0

4(x^2 + 30x - 64) = 0

x^2 + 30x - 64 = 0

Let's use the quadratic formula to finish solving for x.

Plug in a = 1, b = 30, c = -64

$x = \frac{-b\pm\sqrt{b^2-4ac}}{2a}\\\\x = \frac{-30\pm\sqrt{(30)^2-4(1)(-64)}}{2(1)}\\\\x = \frac{-30\pm\sqrt{1156}}{2}\\\\x = \frac{-30\pm34}{2}\\\\x = \frac{-30+34}{2} \ \text{ or } \ x = \frac{-30-34}{2}\\\\x = \frac{4}{2} \ \text{ or } \ x = \frac{-64}{2}\\\\x = 2 \ \text{ or } \ x = -32\\\\$

Recall we made x be positive. This is because a negative walkway width does not make sense. This means we'll ignore x = -32.

The only practical solution is x = 2

Therefore, the walkway is <u>2 feet wide</u>

4 0

2 years ago

The vertices of a triangle are A(4, 1), B(9, 1), C(2, 5). What is the area of this triangle.

kiruha [24]

Hey there!

$\large\boxed{10u^2}$

Formula for the area of a triangle is (1/2)bh.

Base of this triangle is 5, height is 4.

Image attached.

Plug values into the formula:

A = (1/2)(5)(4)

Simplify.

A = (1/2)(20)

A = 10

Area of the triangle is 10 units².

Hope this helps!

6 0

3 years ago

Read 2 more answers

Someone please help me with this question!

Shtirlitz [24]

I'm assuming you're looking for the measure of angle y. Rule is that angle y will be equal to 1/2 of its intercepted arc. That arc measures 360-160-60 which is 140. Half of 140 is 70. So the first choice above is the one you want.

6 0

3 years ago

Find approximate area of the Shaded part of the circle. Use 3.14 for pi.

Ganezh [65]

Let the radius of the bigger circle,R = 6cm
Let the radius of the smaller circle, r = 4cm
Area of the shaded region= area of the bigger circle - area of the smaller circle
Area of the smaller circle = πr^2
3.14×4×4 = 3.14×16 = 50.24cm^2
Area of the larger circle = πR^2
3.14×6×6 = 3.14×36 = 113.04cm^2
Therefore area of the shaded region = 113.04 - 50.24 = 62.8cm^2

6 0

3 years ago