钢琴有52个白键子，黑键子比白键子少16个。)^2w/M9j
（1）黑键子有多少个？)^2w/M9j
算式：提示7r.\3c*V8t6x,f*Y:w:E:i5b+y'U.y)^2w/M9j
答：黑键子有6X/l*J(F9?0U4@(B-q8s个。)^2w/M9j
（2）黑键子和白键子共有多少个？)^2w/M9j
算式：提示6L-Y1S:k0v9~/p/z:R6p:V)^2w/M9j
答：黑键子和白键子共有(@4N.A4I6M个。)^2w/M9j