It takes you 45 minutes to clean the fish tank and it takes your sister 30 minutes. how long does it take the two of you working together to clean the fish tank

Answer:

My 1 minute work = $\frac{1}{45}$

My sisters 1 minute work = $\frac{1}{30}$

My and My sister's 1 minute work = $\frac{1}{45}+\frac{1}{30}$

= $\frac{5}{90}$

= $\frac{1}{18}$

$\therefore$ Me and My sister will finish the work in $\frac{18}{1} =18$ minutes

5 0

3 years ago

The value of 7y–2 is 10 more than the value of 2y

const2013 [10]

Answer:

y=12/5 (in decimal notation y=2.4)

Step-by-step explanation:

the value of 7y-2 = 10 more than 2y

7y-2 = 10+2y

7y-2y = 10+2

5y = 12

y = 12/5

y = 2.4

3 0

4 years ago

Over a certain region of space, the electric potential is V = 4x − 7x2y + 7yz2. Find the expressions for the x, y, z components

Tju [1.3M]

Answer:

Ex = - 4 + 14xy

Ey = 7x² - 7z²

Ez = -14yz

Step-by-step explanation:

The relationship between Electric field Er(x, y, z) and Electric potential, V, is a differential relationship:

Er(x, y, z) = -dV/dr(x, y, z)

Where r(x, y, z) = distance in x, y and z components.

The x component of the electric field is:

Ex = -dV/dx

Given that:

V = 4x - 7x²y + 7yz²

Ex = -dV/dx

Ex = -(4 - 14xy)

Ex = -4 + 14xy

The y component of the electric field is:

Ey = -dV/dy

Ey = -(-7x² + 7yz²)

Ey = 7x² - 7z²

The z component of the electric field is:

Ez = -dV/dz

Ez = -(14yz)

Ez = -14yz

8 0

3 years ago

Use the original price and the markdown to find the retail price. Original price: $145; Markdown: 36% The retail price is $​

Use the original price and the markdown to find the retail price. Original price: $145; Markdown: 36% The retail price is $