Find each sum or difference

(5a+9b) - (4b+2a)

Calculate the area of a circle with a radius of 2 cm and a circle with a radius of 4 cm. leave your answers in terms of pi. when the radius doubles, does the area of the circle double? a. 4π cm2; 8π cm2; no b. 4π cm2; 16π cm2; no c.

11139/238 equals what

How many feet are in 84 inches?

18 more than twice a number is nine less than four times the number?

What is the common factor of the numerator and denominator in the expression (2x+3) (x-4) / (x-4) (x+4) ?

the sum of two consecutive integers is one less than three times the smallest integer. find the two integers

L || m; 1 = 20x + 5; 2 = 24x - 1 what is the value of x

4 percent of x days is 56

What is 100/298 written in its simplest form

Ying eats some yoghurt. The yoghurt contains 192 mg of calcium. This is 16% of the total amount of calcium that Ying should have each day. Work out the total amount of calcium that Ying should have each day, showing your working out (3 marks).