# Worksheet on Changing the Subject of a Formula | Rearranging Formula Worksheets with Answers

If you are about to clear your doubts in homework or need an extra bit of practice this is the place for you. Worksheet on Changing the Subject of a Formula gives you ample practice on different kinds of questions framed on the topic. Try the problems over here on your own and then cross-check with the solutions provided to test where you stand in your preparation. Our Changing the Subject of a Formula Worksheet will complement your preparation and help you perform well in your exams.

## Changing the Subject of a Formula Worksheet with Answers

Change the subject as indicated in the following formulas
1. Distance= Speed × Time make T as the subject.

Solution:

Given Distance= Speed × Time
Move speed to the left side then,
Distance/Speed=Time
Therefore, Time=Distance/speed.

2. p=2(l+b) make l as subject

Solution:

Given p=2(l+b)
Move 2 to the left side and divide it with p.
p/2=l  +b
Subtract b on both sides
p/2-b=l + b – b
p/2-b=l
Therefore, l=p/2-b.

3. Profit=Selling Price – Cost Price make selling Price as subject

Solution:

Move Cost Price to the Left,
Profit + Cost Price=Selling Price
Therefore, Selling Price=Profit + Cost Price.

4. Y=mx + c make x as a subject.

Solution:

Subtract c on both sides.
y-c=mx + c – c
y-c=mx
Divide m on both sides
(y-c)/m=mx/m
(y-c)/m=x
Therefore, x=(y-c)/m.

5. D=b2– 4ac make b as the subject.

Solution:

Given, D = b² – 4ac
Move 4ac to the left side and add it to the D
D + 4ac = b²
By Applying square root on both sides we get,
√(D + 4ac) = √b²
√(D + 4ac) = b
Therefore, b=√(D + 4ac) .
vi) I = (P × R × T)/100 make T as subject
Move 100 to the left side and multiply it with I
I × 100 = PRT
Move RP to the left side and divide it with 100I
100I/RP = T
Therefore, T=100I/RP.

6. Profit Margin=Total Income/Net Sales × 100 make Total Income as the subject.

Solution:

Given Profit Margin=Total Income/Net Sales × 100
Move100 to Left and divide by Profit Margin,
Profit Margin/100=Total income/Net Sales
Move Net Sales to the left,
Net Sales × Profit Margin/100=Total Income
Therefore, Total Income= Net Sales × Profit Margin/100.

7. Income – Savings=Expenses make Savings as the subject.

Solution:

Given,
Income – Savings=Expenses
Move expenses to the Left and savings to the right,
Income – Expenses= Savings.
Therefore, Savings=Income – Expenses.

8. s = mL + r make L the subject by rearranging the formula?

Solution:

Given s=mL + r
First, Subtract r on both sides
s – r = mL + r -r
s-r=mL
Now, Divide m on both sides
(s – r)/m = L
Therefore, L = (s – r)/m.

9. A = 1/2 (l₁ + l₂) h; make l₁ as subject

Solution:

Given that A = 1/2 (l₁ + l₂) h
Move 1/2.h to the left side and divide it with A
2A/h = l₁ + l₂
Move l₂ to the left side and subtract it from 2A/h
2A/h – l₂ = l₁
Therefore, l₁ = 2A/h – l₂.

10. h² = p² + b² make p as a subject.

Solution:

Given that h² = p² + b²
Move b² to the left side and subtract it from h²
h² – b² = p²
Apply square root on both sides
√(h² – b²) = √(p²)
√(h² – b²) = p
Therefore, p = √(h² – b²).

11. A = P {1 + (Rn/100)}; make R as subject

Solution:

Given that A = P {1 + (Rn/100)}
Move P to the left side and Divide it with A.
A/P = 1 + (Rn/100)
Move 1 to the left side and Subtract it with A/P.
A/P – 1 = Rn/100
Move 100 to the left side and Multiply it with A/P – 1.
100(A/P – 1) = Rn
Move n to the left side and Divide it with 100(A/P – 1).
{100(A/P – 1)}/n = R
Therefore, R={100(A/P – 1)}/n .