How do you solve sarah is twice as old as her youngest brother. if the difference between their ages is 15 years. how old is her youngest brother?

Given: x + y = 6. if xe (-15, -6, -1), then which of the following sets of ordered pairs are solutions? © {(-15, -21), (-6, -12), (-1, -7)} [(-15, 21), (-6, , 7)} {(-15, 21), (-6, 12), (-1, -7)}

Plz ( true - false) all triangles have interior angles whose measure sum to 90.

An elevator travels 310 feet in 10 seconds. at that speed, how far can't his elevator travel in 12 seconds?