Using compatible numbers to estimate for the answer 525×31 =

15,900

Step-by-step explanation:

multiple 3 and 0 witch is zero and do it again with will be another zero then you do 3x3 witch is 9 then you multiply 5 and 3 witc is 15 resulting in

15900

the sum of all the angles in a triangle are equal to 180

so you can add   the 3 given angles together to equal 180:

5y + 2y + 2y = 180

or since all three angles have the same letter, combine the 3 angles to equal 180:

9y = 180