Solve the equation |3x + 4| = |3x - 11|

Here we have an equation involving absolute values. As a general rule |a| = +a and |a| = -a. We can apply that to our RHS. In the first case we get that 3x + 4 = 3x - 11, however after we subtract 3x from both sides we are left with 4 = -11, which is obviously false. Therefore, we conclude that there are no solutions for |a| = +a and we move on to |a| = -a. Applying our formula again we have 3x + 4 = - (3x - 11) or 3x + 4 = - 3x + 11. Rearranging we get that 6x = 7 or that x = 7/6.

Answered by Viktoria B. Maths tutor

7558 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

What is the difference between a scalar and vector quantity?


A curve C has equation y = 3x^4 - 8x^3 - 3. Find dy/dx and d2y/dx2. Verify C has a stationary point at x = 2. Determine the nature of this stationary point, giving a reason for the answer.


For a given function F(x), what does the graph of the function F(x+2) look like in comparrison to F(x)?


Consider the curve y=x/(x+4)^0.5. (i) Show that the derivative of the curve is given by dy/dx= (x+8)/2(x+4)^3/2 and (ii) hence find the coordinates of the intersection between the left vertical asymptote and the line tangent to the curve at the origin.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences