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Solve x/(x-7) + 6/(x+4) = 1

Observe neither x=7 or x=(-4) are solutionsMultiply through by (x-7), x + 6(x-7)/(x+4) = (x-7)Subtract x, 6(x-7)/(x+4) = -7Multiply through by (x+4), 6(x-7) = -7(x+4)Therefore, 6x - 42 = -7x - 28Rearrange to...
LD
Answered by Lewis D. • Maths tutor
2841 Views

Differentiate 2^x

2 x = e ln(2^x) = e xln(2) , d/dx(e xln(2) ) = ln(2)e xln(2) = ln(2)*2 x
TD
Answered by Tutor598438 D. • Maths tutor
4840 Views

y=4sin(kx) write down dy/dx.

let u=kx,du/dx=ky= 4 sin(u)dy/du= 4cos(u) dy/dx= du/dx*dy/du = 4kcos(u) =4kcos(kx)
WH
Answered by William H. • Maths tutor
3828 Views

Convert 60km/h to m/s

60x1000=60,000 (convert km into m)60,000/(60x60)= 16.67m/s (here we divide the 60,000m by the number of seconds within an hour, which is 3600)Final answer is therefore 16.67m/s
RL
Answered by Rebecca L. • Maths tutor
16635 Views

Expand the brackets: (2x + 4)(x + 3)

Use the 'crab claw' technique for which order to expand your brackets in (demonstrate by drawing with whiteboard). So start with 2x multiplied by x = 2x 2. Then 2x multiplied by 3 = 6x. Then 4 multiplied by ...
MM
Answered by Molly M. • Maths tutor
4606 Views