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solve the simultaneous equations 3x+7y=18 and 7x+9y=8

3x+7y=18 (eqn 1) -multiply by 7-> 21x+49y=126 (eqn 1*) 7x+9y=8 (eqn 2) -multiply by 3-> 21x+27y=24 (eqn 2*) (eqn 1*)-(eqn 2*) --> 22y=102 therefor y=51/11 sub in this y value back into (eqn1) -->...
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Answered by Radhika S. • Maths tutor
4036 Views

Solve the following simultaneous equations: (1) 4x+y=7 and (2) 3x+2y=9

This question can be answered by the elimination method. I will choose to eliminate 'y' in this case. Firstly, multiply equation (1) by 2, resulting in 8x+2y=14. Now we can subtract eqaution (2): 3x+2y=9 fro...
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Answered by Alex D. • Maths tutor
6197 Views

Solve for x: 4 x + 1 = 2 x + 12

The best way to answer these kind of questions is by moving all the unknowns to one side. In this case, the only unknown is x, so we should start by moving all the x's to one side. Since there are 4x's on th...
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Answered by Tejas K. • Maths tutor
4055 Views

Use your knowledge of the carbon cycle to indicate the effect of deforestation on the carbon dioxide concentration in the atmosphere, and the effect this change will have on the environment.

Atmospheric CO2 is used by trees for photosynthesis. Deforestation means that there are less trees undergoing this photosynthesis reaction, so less CO2 is taken from the atmosphere. The trees that are cut do...
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Answered by Áine C. • Biology tutor
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What is the structure of an atom?

Atoms are really tiny particles that make up all substances in the universe. An element is made of one type of atom. An atom has a small central nucleus made up of smaller sub-atomic particles called protons...
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Answered by Emma T. • Chemistry tutor
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