Factorise (2x)2 + (18x)3, and i have to show working out

Which of these equations, when solved, gives a different value of x than the other three? a9.1 = -0.2x + 10 b10 = 9.1 + 0.2x c10 – 0.2x = 9.1 d9.1 – 10 = 0.2x

What is the best approximation for the area of a circle with a radius of 4 m ? use 3.14 to approximate pi

Whats are the trickiest steps to do when adding or subtracting rational expressions? how does knowledge of rational numbers u in adding and subtracting rational expressions?