1) 5х+17 при х=0; 1; 2.
При x = 0: 5 х+17 = 5 * 0 + 17 = 17
При x = 1: 5 х+17 = 5 * 1 + 17 = 5 + 17 =22
При x = 2: 5 х+17 = 5 * 2 + 17 = 10 + 17 = 27
2)15а+10с при а=3 с=6.
При a = 3, с =6: 15 а + 10 с = 15 * 3 + 10 * 6 = 45 + 60 = 105
3) 2у+7х-4а+9с при у=15, х=10, а=0, с=5
При у=15, х=10, а=0, с=5
2 у+7 х - 4 а + 9 с = 2 * 15 + 7 * 10 - 4 * 0 + 9 * 5 =
30 + 70 - 0 + 45 = 145
4)15а+10х-4у при а=1/2, х=1/4, у=1/10.
при а=1/2, х=1/4, у=1/10
15 а + 10 х - 4 у = 15 * 1/2 + 10 * 1/4 - 4 * 1/10 =
15/2 + 10/4 - 4/10 = 150/20 + 50/20 -8/20 = (150 + 50 - 8)/20 =
= 192/20 = 96/10 = 9 6/10 = 9 3/5
5)(х+у-с):3 при с=1/2, х=1/4, у=1/10.
при с=1/2, х=1/4, у=1/10
(х + у - с ) : 3 = (1/4 +1/10 - 1/2) : 3 =
= (5/20 +2/20 - 10/20) : 3 = - 3/10 : 3 = - 1/10
6)(2а+3к+4с):5 при а=1/3, к=2/5 , с=3/(4.)
(2а+3к+4с):5 = (2 * 1/3 + 3 * 2/5 + 4 *3/4с) : 5 =
= (2/3 + 6/5 + 3) : 5 = (10/15 + 18/15 + 3) : 5 =
= (28/15 + 45/15) : 5 = 73/15 : 5 = 73/75
7)(5/7 к+ 3/4 у+х)*7 при к=5, у=6, х=8.
(5/7 к+ 3/4 у+х)*7 = (5/7 *5 + 3/4 * 6 + 8) * 7 =
= (25/7 + 18/4 + 8) * 7 = (25/7 + 9/2 + 8) * 7 =
= (50/14 + 63/14 + 112/14) * 7 = 225/14 *7 = 225/2 = 112 1/2
8) (5-15а+10х-4у ):4 при а=1/2, х=1/4, у=1/10.
(5-15а+10х-4у ):4 = (5-15 * 1/2 +10 * 1/4 - 4 * 1/10 ) : 4 =
= (5-15/2 +10/4 - 4/10 ) : 4 = (100/20 - 150/20 + 50/20 - 8/20 ) : 4 =
= ( - 8/20 ) : 4 = - 8 / 80 = - 1/10
9) (5х+17)*(3х-4у) при х=1/5, у=1/8.
(5х+17)*(3х-4у) = (5 * 1/5 +17) * (3* 1/5 - 4 * 1/8) =
= (5/5 +17) * (3/5 - 4/8) = 18 * (3/5 - 1/2) = 18 * (6/10 - 5/10) =
= 18 * 1/10 = 18 /10 = 1 8/10
10)(4а-у): (а+у) при а=16/32, у=16/32.
(4а-у): (а+у) = (4 * 16/32 - 16/32) : (16/32 +16/32) =
= (64/32 - 16/32) : (32/32) = 48/32 : 1 = 48/32 = 3/2 = 1 1/2