Factorise $10x+50$10x+50.

Factorise $k^2-81$k2−81.

Factorise $3x+xz-39y-13yz$3x+xz−39y−13yz.

Factorise $x^2+12x+36$x2+12x+36.

Form and solve linear equations and inequations, quadratic and simple exponential equations, and simultaneous equations with two unknowns

Apply algebraic procedures in solving problems