Question

Which of the following is the solution set of 2a + 1 > 9 or a < –1?a){a | a ≤ –1 or a ≥ 4}b){a | –1 ≤ a ≤ 4}c){a | a < –1 or a > 4}d){a | a < –1 or a > 5}

Answer 1

2a + 1 > 9 or a < –1

Solve the left inequality

2a+1 > 9

Subtract 1 from each side

2a+1-1 >9-1

2a > 8

Divide by 2

2a/2 >8/2

a >4

We have a >4 or a < -1

c)

{a | a < –1 or a > 4}