How do you work out the problem 72 divided by 2 plus a equals 40?

Answer 1

72/2 + a = 40

multiply both sides by 2

2(72/2 + a) = (40)2

72 + 2a = 80

subtract 72 from each side

72 - 72 + 2a = 80 - 72

2a = 8

divide both sides integers by 2

(2/2)a = 8/2

a = 4

------------check in original equation

72/2 + (4) = 40

36 + 4 = 40

40 = 40

----------------checks

------------------------------------------------------------------------if you meant

72/(2 + a) = 40

multiply through by 2 + a

72 = 80 + 40a

subtract 80 from each side

- 8 = 40a

divide each side by 40

- 8/40 = a

- 1/5 = a

----------------------check in original equation

72/(2 + [- 1/5]) = 40

now 2 is 10/5

72/(10/5 + [- 1/5]) = 40

72/(9/5) = 40

72/(9/5) is the same as 72 * 5/9

360/9 = 40

40 = 40

-------------------------------checks either way