1i) solve x^2-4x-21=0
Factorise to get (x+3)(x-7)=0
So you can see that x = -3 or x =7
KI
Related Maths GCSE answers
All answers ▸Find the inverse function of f(x) = 5 / (x - 4)
What is 64^1/2 equal to?
The two points (4,9) and (2,3) are on line A. A second line, line B is perpendicular to line A and goes through the point (2,3). What is the equation of line B?
If I know the length of the hypotenuse and one angle, how do i find the length of the side opposite to the angle?