Solve the equation x squared = 3x.
Answer and explanation
Correct answer: B. x = 0 or x = 3
- Step 1: Rearrange: x squared - 3x = 0, so x(x - 3) = 0. Step 2. So x = 0 or x = 3. Answer: x = 0 or x = 3. Why not the others: x = 3 only divides both sides by x and loses the solution x = 0, x = -3 or x = 3 solves x squared = 9 instead, and x = 0 only misses the second factor.
Practise more Algebra and sets.
Free questions with an explanation for every one, and full timed Iraqi Third Intermediate Ministerial Exams mock tests.
More Algebra and sets questions
- What are the solutions of x squared - 6x + 8 = 0?
- Expand and simplify (2x + 7)(2x - 7).
- Expand and simplify (5x + 3)(5x - 3).
- If A = {1, 2, 3, 4, 5} and B = {4, 5, 6, 7}, what is the union of A and B?
- If A = {10, 20, 30} and B = {20, 30, 40, 50}, what is the union of A and B?
- If A = {1, 2, 3, 4, 5, 6} and B = {2, 4, 6}, which set is A - B (the elements of A that are not in B)?