Respuesta :
15. -(-7y + 12) = 7y - 12
16. 1/a = 16/18
cross multiply
16a = 18
a = 18/16 = 9/8
17. 8x - 12 = 4x + 24
8x - 4x = 24 + 12
4x = 36
x = 36/4
x = 9
18. -6b > 42 4b > -4
b < 42/-6 b > -4/4
b < - 7 b > -1
so b < -7 and b > -1
19. 6 more then the product of 8 and n
6 + 8n
20. 45 = 3b + 69
45 - 69 = 3b
-24 = 3b
-24/3 = b
-8 = b
16. 1/a = 16/18
cross multiply
16a = 18
a = 18/16 = 9/8
17. 8x - 12 = 4x + 24
8x - 4x = 24 + 12
4x = 36
x = 36/4
x = 9
18. -6b > 42 4b > -4
b < 42/-6 b > -4/4
b < - 7 b > -1
so b < -7 and b > -1
19. 6 more then the product of 8 and n
6 + 8n
20. 45 = 3b + 69
45 - 69 = 3b
-24 = 3b
-24/3 = b
-8 = b
(15) -(-7y + 12) = +7y - 12
(17) 8x - 12 = 4x + 24---> 8x - 4x = 24 + 12 ---> 4x = 36 ---> x = 9 (18) -6b > 42 ---> b<42/-6 ---> b<8 & 4b > 44 --> b> 11. So, 8>b>11 (20) 45 = 3b + 69 --> 3b = -24 ---> b = -8. Not sure what to do for (16) & (19)
