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4y^2 = 256, Find a value for y

y^2 = 256/4 = 64 therefore, y = sqrt(64) = 8
KP
Answered by Kai P. • Maths tutor
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A circle with centre C has equation x^2+8x+y^2-12y=12. The points P and Q lie on the circle. The origin is the midpoint of the chord PQ. Show that PQ has length nsqrt(3) , where n is an integer.

First complete the square for both x and y. Move all constants to the right hand side. The square root of this is the radius of the circle. The two constants in the completed square bracket show the x and y ...
Answered by • Maths tutor
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Solve the simultaneous equations: 2x + y = 12; x - y = 6

We add the two equations together (left-hand sides and right-hand sides separately). By doing this we get: 2x + y + (x - y) = 12 + 6. By rearranging and simplifying: 3x = 18.If we divide both sides by 3 we g...
RD
Answered by Rebeka D. • Maths tutor
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explain ionic bonding in a giant ionic lattice?

Bonding is about the movement of electrons-electrons are NEGATIVELY charged-the electrons move to allow atoms to become more STABLE by having a full outer shell of electrons-The periodic table is useful to l...
MA
Answered by Maria A. • Chemistry tutor
2635 Views

What are the key different types of selection?

Directional selection occurs when a phenotype at the extreme end of a distribution is favoured and so over time the distribution shifts in the direction of the favoured phenotype. An example of this is the d...
AC
Answered by Abigail C. • Biology tutor
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