Algebra · real student question

Solve the inequality 2x - 3 <= 5 and write the answer in interval notation.

Question

Solve

2x352x-3\le 5

and give the answer in interval notation.

Step-by-step solution

  1. Undo the operations in reverse order. The expression 2x32x-3 multiplies by 22 and then subtracts 33, so to isolate xx you undo the subtraction first and the multiplication second.

  2. Add 33 to both sides. Addition never changes the direction of an inequality:

    2x3+35+32x82x-3+3\le 5+3\quad\Longrightarrow\quad 2x\le 8

  3. Divide both sides by 22. The divisor is positive, so \le stays \le:

    x4x\le 4

  4. Write the interval and check the endpoint. A non-strict inequality includes its boundary, so the bracket is square:

    (,4](-\infty,\,4]

    At x=4x=4: 2(4)3=552(4)-3=5\le 5 \checkmark. At x=0x=0: 35-3\le 5 \checkmark. At x=10x=10: 17≰517\not\le 5 \checkmark.

Answer

x4,i.e. (,4]x\le 4,\qquad\text{i.e. }(-\infty,\,4]

Need to solve a different problem like this? Open the solver →