What is 1/2 - 1/9 I have a picture listed below any answer could really help

7x+8y=-18, 4x-9y=-3 solve the system of equations

Julian wrote the following numeric pattern on the board3,10,17,24,31,38.what numbers of julian's pattern are compound numbers.

If two angles of a triangle have equal measures and the third angle measures 90°, what are the angle measures of the triangle? a. 60°, 60°, 60° b. 45°, 90°, 90° c. 30°, 30°, 90° d. 45°, 45°, 90°