Question

Which graph shows the solution to the inequality -3x-7 <20?

Answer 1

Answer:

Second choice.

Step-by-step explanation:

Option 1: solve the inequality. Add 7 to both sides, and multiply by -3 (don't forget that this makes the inequality switch direction!) to get $x > {27 \over {-3}$ or x > -9

Option 2. Plug 0 in it. You get -7 < 20, which is obviously true. So 0 is in the set of solution and it means B and C are possible solutions. So let's check another easy value. let's say -10. replacing it you get $-3 (-10) -7 < 20$ or $30 -7$. But 23 is obviously greater than 20, which means -10 is not a part of the solution. Correct answer is B