Math Lab
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Solve a Linear Equation

Simple Equations · Class VII

Slide a, b, c to solve a x + b = c. The solution is x = (c - b)/a.

2
type a value
-1010
3
type a value
-2020
11
type a value
-5050
Live values
  • Solution x4
  • Check a*x + b11
xy
  • a x + b

Formulas in this lab

  • Solution x
    c−ba\dfrac{c - b}{a}
  • Check a*x + b
    ax+ba x + b
Tip: The line a x + b crosses the horizontal level c exactly at the solution.

Frequently asked questions

▶How do I solve an equation like ax + b = c?

Subtract b from both sides, then divide by a. So 2x + 3 = 11 gives x = (11 - 3)/2 = 4. The lab uses x = (c - b)/a and shows the answer for any sliders you choose.

▶How do I use the linear equation solver lab?

Slide a, b, c. The lab shows the solution x = (c - b)/a immediately. Try a = 3, b = 2, c = 14 to see x = 4, then verify by plugging in: 3*4 + 2 = 14.

▶Where do simple equations show up in life?

If a pencil costs Rs 5 and you have Rs 50 minus a Rs 10 note already spent, how many pencils can you buy? Solve 5x + 10 = 50 to get x = 8. The lab handles this kind of one-line problem across many sliders.

▶What happens if a is 0?

If a = 0, the equation becomes 0*x + b = c, which has no x to solve for; either b already equals c (infinite solutions) or it does not (no solution). The lab shows NaN when a = 0, reminding you that division by zero is undefined.