<span>Draw a triangle and label is ABC.
Let angle A = x
let angle B = x
let angle C = 2x - 36
2x - 36 means that angle C is 36 degrees less than the sum of angle A and B.
Since the sum of the interior angles of a triangle is 180 degrees, then 2x + 2x - 36 = 180.
combine like terms in that equation and you get 4x - 36 = 180
add 36 to both sides of that equation and you get 4x = 216
divide both sides of that equation by 4 and you get x = 54 degrees
angle A = 54 degrees
angle B = 54 degrees
angle C = 108 - 36 = 72 degrees
54 + 54 + 72 = 108 + 72 = 180 degrees so the angles are good because
they add up to 180 degrees and the third angle is 36 degrees less than
the sum of the other 2.
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He already had 100 into the account so we add that, 25x is derived from the fact that x=the amount of months and 25 is the amount per a month he saves.
