## Welcome to H3 Maths

Blog Support for Growing Mathematicians

## Posts tagged with online mathematics

### Khan Academy – Free Classroom for the World

October11

Salman Khan now has some 3000 online video tutorials to help students around the world (including the children of Bill Gates). Click on the image to read more about this remarkable, free online resource for Mathematics students, etc.

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#### Post Support

NCEA Level 2 Algebra Problem. Using the information given, the shaded area = 9, that is:
y(y-8) = 9 –> y.y – 8y – 9 =0
–> (y-9)(y+1) = 0, therefore y = 9 (can’t have a distance of – 1 for the other solution for y)
Using the top and bottom of the rectangle,
x = (y-8)(y+2) = (9-8)(9+2) = 11
but, the left side = (x-4) = 11-4 = 7, but rhs = y+? = 9+?, which is greater than the value of the opp. side??
[I think that the left had side was a mistake and should have read (x+4)?]