Question

39. a(x + 3) < 5x + 15 - x

Answer 1

x < (15 - 3a) / (a - 4). ( only true if a > 4)

a < (x + 15)/x

Explanation:

a(x + 3) < 5x + 15 - x

ax + 3a < 5x + 15 - x

ax - 5x + x < 15 - 3a

ax - 4x < 15 - 3a

x(a - 4) < 15 - 3a

Dividing both sides by (a - 4):

x < (15 - 3a) / (a - 4)

a < (x + 15)/x

Answer 2

x <
`(15-3a)/(a-4)`; a > 4

a <
`(4x+15)/(x+3)`

Explanation:

ax+3a < 4x + 15

ax - 4x < 15 - 3a

x( a -4) < 15 - 3a

x <
`(15-3a)/(a-4)`

ax + 3a < 5x + 15 -x

ax + 3a < 4x + 15

a( x + 3) < 4x + 15

a <
`(4x+15)/(x+3)`