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Solve:

x 2 + y 2 = 25 y – 3x = 13 Rearrange the second equation: y = 13 + 3x Substitute the rearranged question in the first equation: x 2 + (13 + 3x) 2 = 25 Solve: x 2 + 169 + 9x 2 + 78x - 25 = 0 10x 2 + 78x + 144...
BJ
Answered by Bandana J. • Maths tutor
3648 Views

y = x^3 ln x. Find dy/dx

dy/dx = u.dv/dx + v.du/dxu = x 3 , v = ln xdu/dx = 3x 2 , dv/dx = 1/xdy/dx = 3x 2 lnx + x 2
TU
Answered by Tarun U. • Maths tutor
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Expand the following : (2x+3)(x-1)

We multiply the 2x in the first bracket by everything in the second bracket to give: 2x 2 -2xWe then multiply the 3 in the first bracket by everything in the second bracket to give: 3x-3Putting 2x 2 -2x and ...
SS
Answered by Samuel S. • Maths tutor
3862 Views

How to complete the square to solve quadratic equations?

Equation: x 2 +4x-5=0 (This is in the form ax 2 +2bx+c=0)First divide 2b by 2 (4/2=2)Then put this into (x+b) 2 -(b) 2 +c=0This gives: (x+2) 2 -(2) 2 + -5=0 (remembering +and- makes a -)Simplify to: (x+2) 2 ...
GJ
Answered by George J. • Maths tutor
3302 Views

Write 16× 8^2x as a power of 2 in terms of x.

16 = 2 4 8 2x = (2 3 ) 2x = 2 6x Therefore, 16x8 2x = 2 4 x 2 6x = 2 4+6x
XY
Answered by Xixi Y. • Maths tutor
8705 Views