424.1
the nearest 10th refers to the first decimal place therefore there would only need to be 1 decimal place. and you don’t the round the 1 up when dropping the 2 because the 2 is less than five.
3936/9=440 if that is what you meant
Hi there!

We can solve for x knowing that the sum of interior angles in a triangle is 180°.
The square at the bottom indicates a right angle, or 90°. Therefore:
180 = 90 + x + (x + 10)
Combine like terms:
180 = 100 + 2x
Subtract 100 from both sides:
180 - 100 = 2x
80 = 2x
Divide both sides by 2:
x = 40.
7 because 7•3=21 and if he has as twice much as you 7•2=14 & 14+7=21 books together