Algebra practice question

Answer: 10

Multiply by 6: 3(x + 4) − 2(x − 4) = 30, so x + 20 = 30 and x = 10.

Common wrong answers

If you answered 2

2 comes from 3(x + 4) − 2(x − 4) = 30 with −2(x − 4) taken as −2x − 8.

If you answered 26

26 forgets to multiply the 5 by 6.

If you answered -10

−10 has a sign error in collecting the constants.

More Algebra questions

• Very hard
  For what value of c does the system 3x − 2y = 8 and 9x + cy = 5 have no solution?
• Very hard
  In the system 5x + 4y = 32 and 3x − 2y = 6, what is the value of 8x + 2y?
• Very hard
  The solution set of the inequality |ax − b| ≤ 6, where a and b are constants and a > 0, is 3 ≤ x ≤ 9. What is …
• Very hard
  The function f is linear, and for every value of x, f(x + 2) − f(x) = 6. If f(5) = 4, what is the value of f(0…
• Very hard
  In the system of equations 2x + 3y = 12 and 5x − 2y = k, where k is a constant, the solution (x, y) satisfies …
• Very hard
  In the xy-plane, the system of equations kx + 6y = 12 and 2x + (k − 1)y = 6, where k is a constant, has infini…