Question

The angles of a triangle are X, y and 40. The difference between the two angles X and y is 30. find X and y

Answer 1

Okay so, it's important to remember that all of the interior angles in a triangle add up to 180º

So, x+y+40=180
So, x+y=180-40
So, x+y=140 

We also know that x-y=30

We now solve these two equations simultaneously:

x+y=140
x-y=30

2y=110
y=55

x+55=140
x=140-55
x=85

so x and y are 55º and 85º

Answer 2

the sum of all angles of the triangle is 180 degree
$x + y + 40 = 180 \\ x + y = 180 - 40 \\ x + y = 140 .......equation \: 1\\ but \: as \: per \: question \: here \: given \: x - y = 30 \\ x + y = 140 \\ x - y = 30 \\ (same \: are \: cncell \: out \\ 2y = 110 \\ y = \frac{110}{2} = 55 \\ x + 55 = 140 \\ x = 85 \\ x = 85degree \\ y = 55degree$