Which expression is equivalent to 15x

Round each number to the place of the underlined digit the 4 is underlined in 324,650

dolphi86 [110]

Answer:325,000

Step-by-step explanation:

4 gets rounded up to 5 because of the 6 next to it.

7 0

3 years ago

A pencil at a stationery store costs $1, and a pen costs $1.50. Stefan spent $7 at the store. He bought a total of 6 items. Whic

LekaFEV [45]

Well, the first one, I have never worked with before so I'm sry but I can't help you with that one. 3y + x = 4 (x=1) 2y - x = 6 (x=8)

4 0

3 years ago

Calculate the perimeter of the composite figure. Round your answer to the nearest hundredth. Use 3.14 for $\pi$ .

Elena-2011 [213]

1. Perimeter is 3 + 3 +3 +4 +5 = 18 feet

Area = 3*3 = 9, 1/2*3*4 = 6, 9 + 6 =15 square feet

2. perimeter = 2.5 +2.5+ 2.5+2.5+0.5+0.5 = 11 meters

Area = 3*.5 = 1.5, 3*2=6, 6+1.5 = 7.5 square meters

3. perimeter = 3.14*2*3 = 18.84 +8 = 26.8 inches

Area = 6*4 = 24 + 3.14*3^2 = 28.26 = 28.26 +24 = 52.3 inches

4. surface area = 2*π*6*20+2*π*6^2= 980.2 yards

Volume = π*6^2*20 = 2261.9 cubic yards

5.surface area = 2*(9*7+2*2+2*9) = 190 cm

Volume = 2*7*9 = 126 cubic cm

6. surface area = 2*(11*11+11*11+11*11) = 726 mm

Volume = 11 *11*11 = 1331 cubic cm

3 0

2 years ago

Help please and thank you!!!!!

Zigmanuir [339]

9514 1404 393

Answer:

a) 2 and 4; b) 1&2, 2&3, 3&4
x = 16

Step-by-step explanation:

1a. Vertical angles share a vertex and are composed of opposite rays. Here, angles 2 and 4 are vertical angles.

1b. Consecutively numbered angles are adjacent, as are angles 1 and 5. The pairs of interest can be chosen from ...

1&2, 2&3, 3&4, 4&5, 5&1

__

2. Angles 1 and 3 have the same measure, because they are vertical angles. Then we have ...

78° = (5x -2)°

80 = 5x . . . . . . . divide by °, add 2

16 = x . . . . . . . divide by 5

8 0

2 years ago

Water is being pumped into a conical tank that is 8 feet tall and has a diameter of 10 feet. If the water is being pumped in at

Deffense [45]

The rate of change of the depth of water in the tank when the tank is half

filled can be found using chain rule of differentiation.

When the tank is half filled, the depth of the water is changing at 1.213 ×

10⁻² ft.³/hour.

Reasons:

The given parameter are;

Height of the conical tank, h = 8 feet

Diameter of the conical tank, d = 10 feet

Rate at which water is being pumped into the tank, = 3/5 ft.³/hr.

Required:

The rate at which the depth of the water in the tank is changing when the

tank is half full.

Solution:

The radius of the tank, r = d ÷ 2

∴ r = 10 ft. ÷ 2 = 5 ft.

Using similar triangles, we have;

$\dfrac{r}{h} = \dfrac{5}{8}$

The volume of the tank is therefore;

$V = \mathbf{\dfrac{1}{3} \cdot \pi \cdot r^2 \cdot h}$

$r = \dfrac{5}{8} \times h$

Therefore;

$V = \dfrac{1}{3} \cdot \pi \cdot \left( \dfrac{5}{8} \times h\right)^2 \cdot h = \dfrac{25 \cdot h^3 \cdot \pi}{192}$

By chain rule of differentiation, we have;

$\dfrac{dV}{dt} = \mathbf{\dfrac{dV}{dh} \cdot \dfrac{dh}{dt}}$

$\dfrac{dV}{dh}=\dfrac{d}{h} \left( \dfrac{25 \cdot h^3 \cdot \pi}{192} \right) = \mathbf{\dfrac{25 \cdot h^2 \cdot \pi}{64}}$

$\dfrac{dV}{dt} = \dfrac{3}{5} \ ft.^3/hour$

Which gives;

$\dfrac{3}{5} = \mathbf{\dfrac{25 \cdot h^2 \cdot \pi}{64} \times \dfrac{dh}{dt}}$

When the tank is half filled, we have;

$V_{1/2} = \dfrac{1}{2} \times \dfrac{1}{3} \times \pi \times 5^2 \times 8 =\mathbf{ \dfrac{25 \cdot h^3 \cdot \pi}{ 192}}$

Solving gives;

h³ = 256

h = ∛256

$\dfrac{3}{5} \times \dfrac{64}{25 \cdot h^2 \cdot \pi} = \dfrac{dh}{dt}$

Which gives;

$\dfrac{dh}{dt} = \dfrac{3}{5} \times \dfrac{64}{25 \cdot (\sqrt[3]{256}) ^2 \cdot \pi} \approx \mathbf{1.213\times 10^{-2}}$

When the tank is half filled, the depth of the water is changing at 1.213 × 10⁻² ft.³/hour.

Learn more here:

brainly.com/question/9168560

6 0

2 years ago

Which expression is equivalent to 15x – 2(3x + 6)?