a) (1/2) y + 3 = 7 (1/2) y = 7 -3 = 4 / * 2 y = 8 ======== b) (3/5) y +(2/5) = 4 / * 5 3y + 2 = 20 3y = 20 - 2 = 18 / : 3 y = 6 ==== c) 3(y +2) = 5 / : 3 y + 2 = 5/3 y = 5/3 - 2 y = - 1/3 ============= d) 7( y +3) = 5y + 2 +2y 7y + 21 = 7y + 2 7y - 7y = 2 - 21 0 = - 19 sprzeczność równanie nie ma rozwiązania ============================= e) y/2 + 1/3 = 7/6 / * 6 3y + 2 = 7 3y = 7 -2 = 5 / : 3 y = 5/3 =========== f) y + 3/2 - (1 - y) = 3,5 y + 3/2 -1 + y = 3,5 2y + 1/2 = 3,5 2y = 3,5 - 0,5 = 3 / : 2 y = 1,5 ============ g) (1/5)(y -3) - (2/3)(y - 3/5)+ 1/3 = 2/5 - (1/3)(2y - 3) / * 15 3(y -3) - 10(y -3/5) + 5 = 6 - 5(2y - 3) 3y - 9 - 10y +0,6 + 5 = 6 - 10y + 15 3y = 21 +9 - 5 - 0,6 3y = 24,4 / : 3 y = 8 i 4/3 y = 9 i 1/3 ============= h) co oznacza ? =========== i) y - 2/3 + 1/15 - 2y - 5/3 = 8 - (4y)/5 / *15 15y - 10 +1 - 30y - 25 = 120 - 12 y -15y -34 = 120 - 12y 15y -12y = -34 - 120 3y = - 154 / : 3 y = - 51 i 1/3 ============= j) y - 5/2 +2y +3/5 +1/3 = y + 7/15 + y/2 / *15 15y - 37,5 + 30y + 9 + 5 = 15y + 7 + 7,5 y 45y - 23,5 = 22,5y + 7 45y - 22,5 y = 7+23,5 22,5 y = 30,5 / : 22,5 y = 305/225 y = 61/45 =============
1/2y+3=7/-3 1/2y=4/*2 y=8 3/5y+2/5=4/*5 3y+2=20/-2 3y=18/:3 y=6 3(y+2)=5/:3 y+2=5/3/-2 y=5/3-2 y=-1/3 7y+21=5y+2+2y 7y-5y-2y=2-21 0=-19 rownanie sprzeczne y/2+1/3=7/6/*6 3y+2=7/-2 3y=5/:3 y=5/3 y+3/2-1+y=3,5 2y=3,5-3/2+1 2y=3/:2 y=1,5 1,5y-4,5-2/3y+6/15+1/3=2/5-2/3y+1 1,5y-2/3y+2/3y=2/5+1+4,5-6/15-1 1,5y=4,5/:1,5 y=3 2y-1/2y=1-1 3/2y=0 rownanie sprzeczne y-2y+4y/5=8+2/3-1/15-5/3 /*15 15y-30y+12y=120+10-1-25 -3y=104/:(-3) y=102 2/3 y+2y-y-y/2=7/15+5/2-3/5-1/3 /*30 30y+60y-30y-15y=14+75-18-10 45y=61 y=61/45 chyba sie nie pomylilam :P
