С названием формул не могу(
1.
Ar(Cu²O) = 64x2 + 16 = 144
Mr(Cu) = 128/144 = 0.89(89%)
Mr(O) = 1 - 0.89 = 0.11 (11%)
2.
Ar(Na³PO⁴) = 23x3 + 31 + 16x4 = 164
Mr(Na) = 69/164 = 0.42(42%)
Mr(P) = 31/164 = 0.19(19%)
Mr(O) = 1 - 0.42 - 0.19 = 0.39(39%)
3.
Ar(AlCl³) = 27 + 35.5x3 = 133.5(134)
Mr(Al) = 27/134 = 0.2(20%)
Mr(Cl) = 1 - 0.2 = 0.8(80%)
4.
Ar(Ba³N²) = 137x2 + 14x2 = 302
Mr(Ba) = 274/302 = 0.9(90%)
Mr(N) = 1 - 0.9 = 0.1(10%)
5.
Ar(KNO³) = 39 + 14 + 16x3 = 101
Mr(K) = 39/101 = 0.39(39%)
Mr(N) = 14/101 = 0.14(14%)
Mr(O) = 1 - 0.39 - 0.14 = 0.47(47%)
6.
Ar(Fe(OH)²) = 56 + 2(16 + 1) = 90
Mr(Fe) = 56/90 = 0.62(62%)
Mr(O) = 32/90 = 0.36(36%)
Mr(H) = 1 - 0.62 - 0.36 = 0.02(2%)
7.
Ar(Mg(NO³)²) = 24 + 2(14 + 16x3) = 148
Mr(Mg) = 24/148 = 0.16(16%)
Mr(N) = 28/148 = 0.19(19%)
Mr(O) = 1 - 0.16 - 0.19 = 0.65(65%)
8.
Ar(Al²(SO⁴)³) = 27x2 + 3(32 + 16x4) = 342
Mr(Al) = 54/342 = 0.16(16%)
Mr(S) = 96/342 = 0.28(28%)
Mr(O) = 1 - 0.16 - 0.28 = 0.56(56%)
а) 1/4 и 1/6 (общ.знам.=12, значит 1/4×3, 1/6×2)=3/12 и 2/12
б) 1/4 и 1/10 (общ.знам.=20, 1/4×5, 1/10×2)=5/20 и 2/20
в) 1/6 и 1/8 (общ.знам.=48, 1/6×8, 1/8×6)=8/48 и 6/48
г) 1/6 и 1/9 (общ.знам.=18, 1/6×3, 1/9×2)=3/18 и 2/18
д) 1/10 и 1/15 (общ.знам.=30, 1/10×3, 1/15×2)=3/30 и 2/30
е) 1/10 и 1/25 (общ.знам.=50, 1/10×5, 1/25×2)=5/50и 2/50
ж) 1/30 и 1/40 (общ.знам.=120, 1/30×4, 1/40×3)=4/120 и 3/120
з) 1/30 и 1/50 (общ.знам.=150, 1/30×5, 1/50×3)= 5/150 и 3/150
и) 1/70 и 1/60 (общ.знам.=420, 1/70×6, 1/60×7)=6/420 и 7/420
к) 1/50 и 1/80 (общ.знам.=400, 1/50×8, 1/80×5)=8/400 и 5/400
л) 1/60 и 1/15 (общ.знам.=60, 1/60×1, 1/15×4)=1/60 и 4/60
м) 1/24 и 1/120 (общ.знам.=120, 1/24×5, 1/120×1)=5/120 и 1/120
н) 3/50 и 7/25 (общ.знам.=50, 3/50×1, 7/25×2)=3/50 и 14/50
о) 7/200 и 11/40 (общ.знам.=200, 7/200×1, 11/40×5)=7/200 и 55/200
п) 8/17 и 9/34 (общ.знам.=34, 8/17×2, 9/34×1)=16/34 и 9/34
р) 3/40 и 7/25 (общ.знам.=200, 3/40×5, 7/25×8)=15/200 и 56/200
4 чаш. + 5 пирож. + 2 конф. = 66
Сложим эти уравнения и получим:
6 чаш. + 6 пирож. + 6 конф. = 114
6 · (1 чаш. + 1 пирож. + 1 конф.) = 114
отсюда:
1 чаш. + 1 пирож. + 1 конф. = 114 : 6
1 чаш. + 1 пирож. + 1 конф. = 19 руб
ответ: 19 руб