Question

есеп нужно сократить ыкшымдау а потом выполнить

Answer 1

1) $10 + 3(2x + 5) - 4x = 10 + 6x + 15 - 4x = 2x + 25$

при $x = 7$,

$2x + 25 = 2 \times 7 + 25 = 14 + 25 = 39$

2) $4(5x + 2y) - 13x + 4 = 20x + 8y - 13x + 4 = 7x + 8y + 4$

при $x = 3 \: u \: y = 6$,

$7x + 8y + 4 = 7 \times 3 + 8 \times 6 + 4 = 21 + 48 + 4 = 73$

3) $7(4x + 2) - 6x - 10 = 28x + 14 - 6x - 10 = 22x + 4$

при $x = 12$,

$22x + 4 = 22 \times 12 + 4 = 264 + 4 = 268$

4) $15a + 3(7 - 5a) + 10a - 8 = 15a + 21 - 15a + 10a - 8 = 10a + 13$

при $a = 1$,

$10a + 13 = 10 \times 1 + 13 = 10 + 13 = 23$

5) после 24х какой знак? не понимаю

6) $7(3a + 4b) - 8 - 12a - 20b = 21a + 28b - 8 - 12a - 20b = 9a + 8b - 8$

при $a = 2 \: u \: b = 3$,

$9a + 8b - 8 = 9 \times 2 + 8 \times 3 - 8 = 18 + 24 - 8 = 34$

7) $14(3a + 2) - 28a - 18 = 42a + 28 - 28a - 18 = 14a + 10$

при $a = 3$,

$14a + 10 = 14 \times 3 + 10 = 42 + 10 = 52$

8) $24a + 3b + 2(9a - b) + 3 = 24a + 3b + 18a - 2b + 3 = 42a - b + 3$

при $a = 1 \: u \: b = 2$,

$42a - b + 3 = 42 \times 1 - 2 + 3 = 42 - 2 + 3 = 43$

9) $7(10a + 3) - 64a + 1 = 70a + 21 - 64a + 1 = 6a + 22$

при $a = 0$,

$6a + 22 = 6 \times 0 + 22 = 22$

10) $2(15x + 4) + 3(x - 2) = 30x + 8 + 3x - 6 = 33x + 2$

при $x = 5$,

$33x + 2 = 33 \times 5 + 2 = 165 + 2 = 167$

11) $3a + 8(2a + 1) - 19a = 3a + 16a + 8 - 19a = 19a - 19a + 8 = 8$

при любом значении a, значение выражения будет равно 8

12) $8x + 3(x + 7) - 5x = 8x + 3x + 21 - 5x = 6x + 21$

при $x = 2$,

$6x + 21 = 6 \times 2 + 21 = 12 + 21 = 33$