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How do you factorise quadratic equations by completing the square?

Divide the term in x by 2 and then put it in the bracket which will be squared. The last term from that expansion needs to be adjusted for.
DM
Answered by Dario M. • Maths tutor
3552 Views

Expand: (3x-1)(x+5)(4x-3)

(3x^2+14x-5)(4x-3)= 12x^3-9x^2+56x^2-42x-20x+15=12x^3+47x^2-62x+15
WH
Answered by William H. • Maths tutor
7889 Views

Express root(125^x)/5^(2x-1) in terms of 5^a where a is an expression in terms of x.

root(125^x) = 125^(x/2) = 5^(3x/2) 5^(3x/2) / 5^(2x-1) = 5^(3x/2 - 2x +1) = 5^(-x/2 + 1)
SN
Answered by Sophie N. • Maths tutor
4080 Views

Find the cross product between two unit vectors a and b.

First write out the unit vectors in I, j, and k form. Then put these values into a matrix. Then find the determinant of the matrix. Then you will have reached your answer. I couldn't figure out how to show t...
NL
Answered by Nicholas L. • Maths tutor
1833 Views

Tom has a circular garden of radius 30m and he wishes to cover it with fertiliser. Boxes of fertiliser cover 28m^2 of garden. How many boxes will Tom need to cover his entire garden?

Area of a Circle = π radius 2 Area of Garden = π 30*30 = 2827.43 m 2 Boxes needed = 2827.43/28 = 101
OR
Answered by Oliver R. • Maths tutor
3200 Views