KS3 algebra equations with brackets - working out the value of x

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Maths Quiz - Level 5-6 Algebra - Equations with Brackets (Questions)

Algebra is a part of your KS3 Maths journey that you'll need to get the hang of. This quiz is all about equations (a big part of algebra), specifically ones with brackets. Get ready to figure out the value of x or other letters like a or b by shuffling around letters and numbers. It's like a beginner's guide to equations, helping you grasp the concept.

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The secret to solving equations is keeping them balanced, like an old-fashioned set of scales. The equal sign is the pivot, and if you remove something from one side, balance it out on the other. Your goal is to arrange things so the variable is on one side and numbers on the other, making it easier to find their values.

Progress through the quiz, take your time, and have fun solving equations - good luck!

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3 x a + 4 = 6 is the same as which of the following?

[ ]	3 x a = 6 - 4
[ ]	3 x a = 6 / 4
[ ]	3 x a = 6 + 4
[ ]	3 x a = 6 x 4

3b - 16 + b = 1 is the same as which of the following?

[ ]	4b = 1 - 16
[ ]	4b = 1 / 16
[ ]	4b = 1 + 16
[ ]	4b = 1 x 16

3a + 6 + b = 3a + 5 is the same as which of the following?

[ ]	b = 3a - 3a + 5 - 6
[ ]	b = 3a + 3a + 5 - 6
[ ]	b = 3a - 3a - 5 + 6
[ ]	b = 3a - 3a + 5 + 6

2x - 6 could be written as which of the following?

[ ]	(x - 3)2
[ ]	2(x - 3)
[ ]	Either of the above
[ ]	Neither of the above

If 6a - 5 = 20, which of the following is incorrect?

[ ]	6a = 25
[ ]	a = 25 / 6
[ ]	a = 4¹⁄₆
[ ]	a = 4.25

5(a - 4) is the same as which of the following?

[ ]	5a + 20
[ ]	5a - 20
[ ]	5a - 4
[ ]	5a4

Look at the following equation and choose the correct answer when the brackets have been expanded: 4(a + 3) = 5(b - 8)

[ ]	4a - 12 = 5b - 40
[ ]	4a - 12 = 5b + 40
[ ]	4a + 12 = 5b - 40
[ ]	4a + 12 = 5b + 40

If 4(x - 5) = 10, what is the value of x?

[ ]	5
[ ]	7.5
[ ]	10
[ ]	15

If 16(a + 7) = 128, what is the value of a?

[ ]	1
[ ]	2
[ ]	3
[ ]	4

10.

If 5(x + 2) = -35, what is the value of x?

[ ]	-5
[ ]	-9
[ ]	-10
[ ]	10

You can find more about this topic by visiting BBC Bitesize - Equations

Maths Quiz - Level 5-6 Algebra - Equations with Brackets (Answers)

3 x a + 4 = 6 is the same as which of the following?

[x]	3 x a = 6 - 4
[ ]	3 x a = 6 / 4
[ ]	3 x a = 6 + 4
[ ]	3 x a = 6 x 4

When the 4 crosses the equals sign it changes from + 4 to - 4

3b - 16 + b = 1 is the same as which of the following?

[ ]	4b = 1 - 16
[ ]	4b = 1 / 16
[x]	4b = 1 + 16
[ ]	4b = 1 x 16

When - 16 crosses the equals sign it changes to + 16

3a + 6 + b = 3a + 5 is the same as which of the following?

[x]	b = 3a - 3a + 5 - 6
[ ]	b = 3a + 3a + 5 - 6
[ ]	b = 3a - 3a - 5 + 6
[ ]	b = 3a - 3a + 5 + 6

The correct answer could be further simplified to b = -1

2x - 6 could be written as which of the following?

[ ]	(x - 3)2
[ ]	2(x - 3)
[x]	Either of the above
[ ]	Neither of the above

Basically, 2x - 6 is the same as (x - 3) times 2

If 6a - 5 = 20, which of the following is incorrect?

[ ]	6a = 25
[ ]	a = 25 / 6
[ ]	a = 4¹⁄₆
[x]	a = 4.25

You will often find that you have a term such as 6a and you need to separate the 6 from the a in order to determine the value of a

5(a - 4) is the same as which of the following?

[ ]	5a + 20
[x]	5a - 20
[ ]	5a - 4
[ ]	5a4

Removing brackets this way is referred to as 'expanding the brackets'. In this case the 5 outside of the brackets must be multiplied by BOTH the a and the - 4 that are inside the brackets

Look at the following equation and choose the correct answer when the brackets have been expanded: 4(a + 3) = 5(b - 8)

[ ]	4a - 12 = 5b - 40
[ ]	4a - 12 = 5b + 40
[x]	4a + 12 = 5b - 40
[ ]	4a + 12 = 5b + 40

We're multiplying the values in brackets by the numbers in front of them

If 4(x - 5) = 10, what is the value of x?

[ ]	5
[x]	7.5
[ ]	10
[ ]	15

4x - 20 = 10 and therefore 4x = 30

If 16(a + 7) = 128, what is the value of a?

[x]	1
[ ]	2
[ ]	3
[ ]	4

16a + 112 = 128 and therefore 16a = 16

10.

If 5(x + 2) = -35, what is the value of x?

[ ]	-5
[x]	-9
[ ]	-10
[ ]	10

5 x -7 = -35