It is said that whoever can master equations with parentheses by heart has analytical thinking in his little finger. See for yourself – this example is the perfect test of both attention and patience.

Before you start reading, prepare your brain for a bit of arithmetic. Algebra is one of those subjects that many people like to put off until later – it’s just that regular practice with equations and logic problems keeps the thinking fresh and sharp. And this example is proof that even a seemingly straightforward problem may not be as easy as it first appears. Parentheses, signs, and rearranging terms can trouble even those with a lot of math experience.

What’s in store for you today?

The linear equation you are facing is:-3(5x – 4) + 7 = 2x + 4(3x + 1) – 6. The challenge is to unroll all the parentheses, correctly collect the like terms on each side of the equation and calculate the value of x. No tricks or special formulas – just pure, honest algebra. But watch out for the signs when unrolling the parentheses, that’s where the errors are most often hidden, and they will throw the whole result off.

Calculate the example. ━━ Calculate the example. ( Source: Shutterstock )

The correct solution

How did you do? Did you achieve the correct result? Now you can go through the procedure step by step.

The correct result is x = 21/29.

Left side: -3(5x – 4) + 7 = -15x + 12 + 7 = -15x + 19. Right side: 2x + 4(3x + 1) – 6 = 2x + 12x + 4 – 6 = 14x – 2. Now move the terms: -15x – 14x = -2 – 19, so – 29x = -21, and the result is x = 21/29. If you hit it, congratulations – the parentheses didn’t catch you off guard.

Share this example with someone close to you – whether a friend, sibling or work colleague. Math challenges like this are great for exercising memory, improving concentration, and keeping the brain in shape, no matter what your age. And if one equation wasn’t enough for you, you’ll find more puzzles and IQ tests on our website that will test your logical thinking properly.