Mastering Change of Subject in Equations

Rearrange the formula A = πr² to make r the subject.

• r = πA

• r = A/π

• r = 2πA

• r = √(A/π)

If F = ma, change the subject to a.

• a = F/m

• a = F - m

• a = F + m

• a = m/F

Given the equation C = 2πr, express r in terms of C.

• r = 2C / π

• r = C / (2π)

• r = C / π

• r = C / (4π)

From the formula V = lwh, solve for h.

• h = V - (lw)

• h = V * (lw)

• h = V / (lw)

• h = V + (lw)

If P = 2(l + w), change the subject to l.

• l = P/2 - 2w

• l = P - 2w

• l = (P/2) - w

• l = P/2 + w

Rearrange the equation I = V/R to make V the subject.

• V = I * R

• V = I / R

• V = I + R

• V = R - I

From the formula A = P(1 + rt), express t in terms of A, P, and r.

• t = P(1 + A/r)

• t = ((A/P) - 1) / r

• t = A / (P + r)

• t = A - Pr

If d = rt, change the subject to r.

• r = d/t

• r = d + t

• r = d * t

• r = d - t

Given the equation s = ut + 0.5at², solve for a.

• a = (s + ut) / t²

• a = (s - ut) / t

• a = 2(s - ut) / t²

• a = s / (ut + 0.5t²)

Rearrange the formula E = mc² to make m the subject.

• m = c²/E

• m = E/c²

• m = E * c

• m = E + c²