En resumen

D. 1. 2x + 9 = 37 2. X / 2 + 4 = 12 3. X - 15 = 75 4. 3 * a = 42 5. 3b + 8 = 29 E. 1. x + 2x = 45 3x = 45 x = 45 / 3 x = 15 Comprobación x + 2x = 45 15 + 2 * 15 = 45 15 + 30 = 45 45 = 45 2.

Mejor respuesta

4

D. 1.

2x + 9 = 37

2.

X / 2 + 4 = 12

3.

X - 15 = 75

4.

3 * a = 42

5.

3b + 8 = 29

E.

1. x + 2x = 45 3x = 45 x = 45 / 3

x = 15

Comprobación x + 2x = 45

15 + 2 * 15 = 45 15 + 30 = 45 45 = 45

2.

A + 3a = 384 4a = 384 a = 384 / 4 a = 96

comprobación

a + 3a = 384

96 + 3 * 96 = 384

96 + 288 = 384 384 = 384

3.

5 * a + 6 = 46 5 * a = 46 - 6 5 * a = 40 a = 40 / 5 a = 8

comprobación 5 * a + 6 = 46

5 * 8 + 6 = 46 40 + 6 = 46 46 = 46

4.

(x + 14) * 11 = 220 x + 14 = 220 / 11 x + 14 = 20 x = 20 - 14 x = 6

comprobación (x + 14) * 11 = 220 (6 + 14) * 11 = 220 20 * 11 = 220

220 = 220.