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How do you expand (2x+9)^2?

(2x+9)² = (2x+9)(2x+9) Use FOIL to expand these brackets: First - (2x+9)(2x+9) --> 4x² Outside - (2x+9)(2x+9) --> 4x² + 18x Inside - (2x<...

Answered by Alec M. • Maths tutor

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What is the difference between exothermic and endothermic reactions?

The first law of thermodynamics states that energy can neither be created nor destroyed. Energy has to be used when breaking bonds, yet is formed when making bonds. This means that there will be an overal...

Answered by Alec M. • Chemistry tutor

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How may cells be specialised to their function?

Despite animal cells all having a nucleus (for genetic information storage and reproduction), a cytoplasm (for structure), mitochondria (for aerobic respiration), ribosomes (for protein synthesis) and a c...

Answered by Alec M. • Biology tutor

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5x - 2 > 3x + 11

Firstly we need to get all the x's on one side and the numbers on the other side. So if we add 2 to both sides we get 5x > 3x + 13. Now as we want the x's on the right hand side, we need to subtract bo...

Answered by Sam C. • Maths tutor

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A student reacts calcium carbonate with hydrochloric acid. Design an experiement that would allow the student to determine the rate of reaction. Draw the set up.

The reaction between calcium carbonate and hydrochloric acid produces carbon dioxide. The carbon dioxide could be collected in a gas syringe or in a measuring tube inverted and filled with water. The ra...

Answered by Katy A. • Chemistry tutor

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