a sedimentary rock is formed from mud, sand, and pebbles that are deposited in layers upon layers that eventually turn to rock. How is the composition of a rock different from that of cells in living organisms?​

As sedimentation continues, the earlier deposited sediments are laden with an increasing overburden. ... Dissolved minerals in the ground water precipitate (crystallize) from water in the pore spaces forming mineral crusts on the sedimentary grains, gradually cementing the sediments, thus forming a rock.

Step-by-step explanation:

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.