How do you solve the inequality 3(t - 3) + 1 ≥ 7 and 2(t + 1) + 3 ≤ 1?

1 Answer
Aug 6, 2017

See a solution process below:

Explanation:

Solve First Inequality

Begin by solving the first inequality:
color(red)(3)(t - 3) + 1 >= 7

(color(red)(3) xx t) - (color(red)(3) xx 3) + 1 >= 7

3t - 9 + 1 >= 7

3t - 8 >= 7

3t - 8 + color(red)(8) >= 7 + color(red)(8)

3t - 0 >= 15

3t >= 15

(3t)/color(red)(3) >= 15/color(red)(3)

(color(red)(cancel(color(black)(3)))t)/cancel(color(red)(3)) >= 5

t >= 5

Solve Second Inequality

Next, we can solve the second inequality for t:

color(red)(2)(t + 1) + 3 <= 1

(color(red)(2) xx t) + (color(red)(2) xx 1) + 3 <= 1

2t + 2 + 3 <= 1

2t + 5 <= 1

2t + 5 - color(red)(5) <= 1 - color(red)(5)

2t + 0 <= -4

2t <= -4

(2t)/color(red)(2) <= -4/color(red)(2)

(color(red)(cancel(color(black)(2)))t)/cancel(color(red)(2)) <= -2

t <= -2

**The Solution Is:

t < -2; t >= 5

Or, in interval notation:

(-oo, -2]; [5, +oo)