4 + 90 = 94
385
4 + 5 - 90 + 76 = -5
80 + 90 + 100 + 110 = 380/4 = 95
4 + 86 = 90
3+6+7+89+4+5+7+9+90+67 = 287
90
45 x 2 = 90 4 + 6 = 10 = 100
4x + 4 + 5x - 22 = 90 combined like terms 9x - 18 = 90 +18 +18 9x = 108 /9 /9 divide by 9 on both sides x = 12 plug in and check (4 * 12) + 4 + (5 * 12) - 22 = 90 48 + 4 + 60 -22 = 90 90 = 90
480
90.
(13+47+31+10+20+50+36+54+122+4)/60==(13+47+31+[10+20+50]+36+54+122+4)/60 =(13+47+31+80+[36+54]+122+4)/60=([13+47]+31+80+90+122+4)/60=(60+31+80+90+122+4)/60=(31+122+4+60+80+90)/60=(153+4+60+80+90)/60=(157+60+80+90)/60=(157+140+90)/60=(157+230)/60=387/606 min. 27 sec.
270