Dan wanted to find an equivalent to the expression 3(x + 7) +5. His work is show Step 1: 3(x+ 7) +5= (3x + 7) +5
Step 2: 3(x + 7) + 5 = 3x + ( 7+5)
Step 3: 3(x + 7) + 5 = 3x + 12
In which step, if any, did Dan first make an error?
Step 1
Step 2
© Step 3
Dan did not make any mistakes in his work.

The volume, v, of a rectangular prism is determined using the formula, where / is the length, w is the width, and his theheight of the prism. carltren solves for w and writes the equivalent equation w=using this formula, what is the width of a rectangular prism that has a volume of 138.24 cubic inches, a height of 9.6 inches,and a length of 3.2 inches?

Alex measured the length of an item to be 3.7 cm. the actual length is 3.5 cm. what is alex’s percent error?

Submarines control how much they float or sink in the ocean by changing the volume of air and water contained in large ballast tanks. when the tanks are completely full of water, the submarine increases its overall mass and sinks down to the bottom. when the tanks are completely full of air, the submarine reduces its overall mass and floats to the surface. depending on the density of the seawater surrounding the submarine, it will pump seawater in or out of the tanks in order to achieve the same overall density as the sea water and float neutrally in the water. the volume of the submarine never changes. when the tanks are completely full of water, a submarine with a volume of 7.8\times10^3\text{ m}^37.8×10 3 m 3 7, point, 8, times, 10, start superscript, 3, end superscript, space, m, start superscript, 3, end superscript has a total mass of 8\times10^6\text{ kg}8×10 6 kg8, times, 10, start superscript, 6, end superscript, space, k, g. the density of the seawater is 10^3\text{ kg/m}^310 3 kg/m 3 10, start superscript, 3, end superscript, space, k, g, slash, m, start superscript, 3, end superscript. to make that submarine float neutrally, and neither float nor sink in the ocean, what volume of water does that submarine need to subtract from its tanks?