Expand and simplify (3 + 4*root5)(3 - 2*root5)
Using FOIL to expand the brackets we get
9 - 6root5 + 12root5 + 8*root5^2
Square rooting then squaring a number cancels out, so we are left with 8*5 or 40 for the last term.
Simplify to give
9 + 6*root5 + 40
6*root5 + 49
CM
Related Maths A Level answers
All answers ▸Differentiate y=x^2+4x+12
Find the two real roots of the equation x^4 -5=4x^2 Give the roots in an exact form.
Solve the equation 3sin^2(x) + sin(x) + 8 = 9cos^2(x), -180<X<180. Then find smallest positive solution of 3sin^2(2O-30) + sin(2O-30) + 8 = 9cos^2(2O-30).
differentiate: y=[xcos(x^3)]/[(x^4 + 1)^3] with respect to x