Algebra: Changing the Subject of a Formula

Changing the Subject

• To change the subject of a formula, rearrange the formula to isolate the desired variable.

Equipment Needed

• Pen

Guidance

• Read each question carefully before answering
• Check answers for accuracy
• Always show workings

Video Tutorial

• Available at www.corbettmaths.com/contents, Video 7

Answers and Video Solutions

• Available at www.corbettmaths.com/contents

Formulas and Solutions

• Make d the subject of e = d + 5: d = e - 5
• Make w the subject of t = 2w: w = t/2
• Make c the subject of a = c - w: c = a + w
• Make x the subject of y = 3x: x = y/3
• Make w the subject of y = 3w - a: w = (y + a)/3
• Make w the subject of s = a/w: w = a/s
• Make u the subject of v = u + 10t: u = v - 10t
• Make t the subject of v = u + 10t: t = (v - u)/10
• Given x + y = 1, y = 1 - x
• Make x the subject of y = k/x: x = ky
• Make t the subject of m = 3t - 8: t = (m + 8)/3
• Perimeter of a rectangle, P = 6x + 2
• Express x in terms of P: x = (P - 2)/6
• Make m the subject of hs = 4m: m = hs/4
• Express v in terms of t: v = 4t + 1
• Make d the subject of c = 4d + 5: d = (c - 5)/4
• Make g the subject of a = g: g = a
• Make y the subject of k = y3 + a: y = ∛(k - a)
• Make x the subject of C = 4x + 5y: x = (C - 5y)/4
• Make y the subject of 3y = 2x: y = 2x/3
• Make x the subject of 2x - y + 1 = 0: x = (y - 1)/2
• Make a the subject of 8 + c = 3 - a: a = 3 - c - 8
• Make w the subject of a = 6/(w - 2): w = (6/a) + 2
• Make t the subject of r = 3w + t: t = r - 3w
• Make a the subject of a2 + b2 = c2: a = √(c2 - b2)
• Make p the subject of ac = πp: p = ac/π
• Make s the subject of v2 = u2 + 2as: s = (v2 - u2)/(2a)
• Make y the subject of w = 3/(5y - 8): y = (8 + 3/w)/5

Learn how to change the subject of a formula by rearranging it to isolate the desired variable. Practice with examples and video tutorials.