# Worksheet on Change of Subject

Practice the questions given in the worksheet on change of subject

When a formula involving certain variables is known, we can change the subject of the formula.

What is the subject in each of the following questions? Change the subject as indicated.

1. v = u + at; make a the subject.

2. P = $$\frac{m}{m + n}$$; make m the subject.

3. A = π(R2 – r2); make R the subject.

4. $$\frac{1}{R}$$ = $$\frac{1}{r_{1}}$$ + $$\frac{1}{r_{2}}$$; make r2 the subject.

5. s = ut + $$\frac{1}{2}$$at2; make a the subject.

6. In the formula S= 2(lb + bh + lh), S is the subject. Write the formula with h as the subject.

7. If l = a + (n – 1)d, write the formula for the subject n.

8. If 2ax + 3b2 = 2bx + 3a2, write the formula for x in terms of a, b in the simplest form.

Answers for the worksheet on change of subject  are given below:

1. v; a = $$\frac{v - u}{t}$$

2. P; m = $$\frac{nP}{1 - p}$$

3. A; R = $$\pm \sqrt{\frac{A}{\Pi} + r^{2}}$$

4. R; r2 = $$\frac{Rr_{1}}{r_{1} - R}$$

5. s; a = $$\frac{2(s - ut)}{t^{2}}$$

6. h = $$\frac{s - 2lb}{2(b + l)}$$

7. n = 1 + $$\frac{l - a}{d}$$

8.x = $$\frac{3}{2}$$(a + b)