151°减142.1°加10°66分等于多少 125.6°减25°24′等于多少

1°=60′,1′=60″
151°-142.1°+10°66′
=(150°+60′)-(142°+0.1×60′)+(11°+6′)
=(150°+60′)-(142°+6′)+(11°+6′)
=(150°-142°+11°)+(60′-6′+6′)
=19°+60′
=20°
125.6°-25°24′
=(125°+0.6×60′)-(25°+24′)
=(125°+36′)-(25°+24′)
=(125°-25°)+(36′-24′)
=100°+12′
=100°12′

(1) 20°
(2) 100°12′