51988 rounded to the nearest 10 thousand

If a and b are the measures of two first quadrant angles and sin a = 4/9 and sin b = 2/5 find sin(a+b).

After applying the composition r0.90 ry to rs what are the coordinates of r' and s'? a.r'(–3, 1),  s'(–3, 5)b.r'(–1, 3),  s'(–5, 3)c.r'(1, 3),  s'(5, 3)d.r'(5, 3),  s'(1, 3)

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.