Maths Ext 2. Rearranging equations

Question 1

Calculate the value of A.

5A = 10

Answer 1

5 x A = 10

so A = 10 / 5

so A = 2

Question 2

Calculate the value of A.

3A = 12

Answer 2

3 x A = 12

so A = 12 / 3

so A = 4

Question 3

Calculate the value of A.

6A + 4 = 46

Answer 3

6A + 4 = 46

so 6A = 46 - 4 = 42

so A = 42 / 6

so A = 7

Question 4

Calculate the value of A.

8A - 7 = 57

Answer 4

8A - 7 = 57

so 8A = 57 + 7 = 64

so A = 64 / 8

so A = 8

Question 5

Calculate the value of A.

25A + 3 = 103

Answer 5

25A + 3 = 103

so 25A = 103 - 3 = 100

so A = 100 / 25

so A = 4

Question 6

Calculate the value of N.

(3+4) + 17N = 41

Answer 6

(3+4) + 17N = 41

so 7 + 17N = 41

so 17N = 41 - 7 = 34

so N = 34 / 17

so N = 2

Question 7

Calculate the value of N.

(3 x 4) + 12N = 156

Answer 7

(3 x 4) + 12N = 156

so 12 + 12N = 156

so 12N = 156 - 12 = 144

so N = 144 / 12

so N = 12

Question 8

Calculate the value of N.

3N + 4N + 5N = 36

Answer 8

3N + 4N + 5N = 36

So 12N = 36

so N = 36 / 12

so N = 3

Question 9

Calculate the value of N.

12N x 2 + 4 = 28

Answer 9

Remember we need to do the multiplication first.

12N x 2 + 4 = 28

so 24N + 4 = 28

so 24N = 28 - 4 = 24

so N = 24 / 24

so N = 1

Question 10

Calculate the value of N.

3N + (4N x 2) + 2 = 123

Answer 10

3N + (4N x 2) + 2 = 123

so 3N + 8N + 2 = 123

so 11N + 2 = 123

so 11N = 123 - 2 = 121

so N = 121 / 11

so N = 11

Question 11

If A = 3, calculate the value of B.

B = 3A + 7

Answer 11

Swap A for the actual value 3:

B = 3A + 7

B = (3 x 3) + 7

so B = 9 + 7

so B = 16

Question 12

If A = 12, calculate the value of B.

B = 3A + 7

Answer 12

Swap A for the actual value 12:

B = 3A + 7

B = (3 x 12) + 7

so B = 36 + 7

so B = 43

Question 13

If A = 15, calculate the value of B.

B = 4A - 12

Answer 13

Swap A for the actual value 15:

B = 4A - 12

B = (4 x 15) - 12

so B = 60 - 12

so B = 48

Question 14

If A = 21, calculate the value of B.

B = 100 - 3A

Answer 14

B = 100 - 3A

so B = 100 - (3 x 21) = 100 - 63

so B = 37

Question 15

If A = 9, calculate the value of B.

B = 2² x 2A

Answer 15

B = 2² x 2A

so B = 4 x 2A

so B = 8A

so B = 8 x 9

so B = 72

Question 16

Rearrange this equation in terms of B.

A = B + 6

Answer 16

A = B + 6

so A - 6 = B

or B = A - 6

Question 17

Rearrange this equation in terms of B.

A = 4B

Answer 17

A = 4B

so A / 4 = B

or B = A / 4

Question 18

Rearrange this equation in terms of B.

A = 4B + 3

Answer 18

A = 4B + 3

so A - 3 = 4B

so (A - 3) / 4 = B

or B = (A - 3) / 4

Question 19

Rearrange this equation in terms of B.

9A = 3B - 9

Answer 19

9A = 3B - 9

so 9A + 9 = 3B

so (9A + 9) / 3 = B

so 3A + 3 = B

or B = 3A + 3

Question 20

Rearrange this equation in terms of B.

2A = 8B - 9 + 2B + 7

Answer 20

2A = 8B - 9 + 2B + 7

so 2A = 10B -2

so 2A - 2 = 10B

so (2A -2) / 10 = B

or B = (2A -2) / 10