During one month, a homeowner used 600 units of electricity and 100 units of gas for a total cost of 390. The next month, 400 units of electricity and 250 units of gas were used for a total cost of $326. Find the cost per unit of gas.

$0.36

Step-by-step explanation:

Let the cost per unit of electricity  = e

Let the cost per unit of gas  = g

  a homeowner used 600 units of electricity and 100 units of gas for a total cost of 390;

   600e + 100g  = 390  ----- i

  400 units of electricity and 250 units of gas were used for a total cost of $326.

     400e + 250g  = 326 ----- ii

Now we have two equations, and we solve for g;

     600e + 100g  = 390  ----- i

     400e + 250g  = 326 ----- ii  

Multiply equation i by 4 and equation ii by 6;

    2400e + 400g  = 1560 ---- iii

    2400e + 1500g  = 1956 ---- iv

Subtract equation iii from iv;

                  1100g  = 396

                       g  =   = 0.36

Cost per unit of gas $0.36

answer: the answer is (b) amie should have multiplied

step-by-step explanation: given a sphere and a cylinder with same radius and height.

let, 'r' be the radius of the cylinder and sphere and 'h' be the height of the cylinder. according to the question,

r = h.

now, the volume of the sphere will be

and the volume of the cylinder will be

therefore, we have

thus, ammie should have multiplied the volume of the sphere

the volume is the product of the area of the base, 3x(3x+4), and the height, 3x-1

step-by-step explanation: