Kiran wrote the expression x-10 for this number puzzle: "Pick a number, add -2, and multiply by 5."

Lin thinks Kiran made a mistake.

How can she convince Kiran he made a mistake?

If you pick the number 2, you will get (2) - 10 = 8

But the way he said it, it would be:  (2) - 2 * 5 = 0

The correct way would be to write the expression:  (x - 3) * 5

according to the triangle sum theorem, all the angles in a triangle must add up to 180 degrees. if we know one angle is already 90, we do 180-90=90. the other 2 angles must add up to 90, exactly.

step-by-step explanation: