Worksheet on algebraic substitution with examples and practice problems.

Question 1
(a) 2x = 2(3) = 6
(b) 2x - 1 = 2(3) - 1 = 5
(c) 3x - 2y = 3(3) - 2(2) = 9 - 4 = 5
(d) 3(x + y) = 3(3 + 2) = 3(5) = 15
(e) x² - y = (3)² - 2 = 9 - 2 = 7
(f) x³ + 9y² = (3)³ + 9(2)² = 27 + 9(4) = 27 + 36 = 63
(g) 5y = 5(2) = 10
(h) 3xy - x = 3(3)(2) - 3 = 18 - 3 = 15
(i) (x - y)² = (3 - 2)² = (1)² = 1
(j) 12/y = 12/2 = 6
(k) (x + y)² = (3 + 2)² = (5)² = 25

Question 2
(a) 3y = 3(-2) = -6
(b) 3y - x = 3(-2) - 3 = -6 - 3 = -9
(c) x - y = 3 - (-2) = 3 + 2 = 5
(d) 7(x + y) = 7(3 + (-2)) = 7(1) = 7
(e) x² - 9y = (3)² - 9(-2) = 9 + 18 = 27
(f) y³ + 3x - 1 = (-2)³ + 3(3) - 1 = -8 + 9 - 1 = 0
(g) y + x = -2 + 3 = 1
(h) x/2 = 3/2
(i) x - 2y = 3 - 2(-2) = 3 + 4 = 7
(j) (3x - y)/10 = (3(3) - (-2))/10 = (9 + 2)/10 = 11/10
(k) y/(3x) = (-2)/(3*3) = -2/9
(l) (3x - y)/2 + 6x = (3(3) - (-2))/2 + 6(3) = (9 + 2)/2 + 18 = 11/2 + 18 = 5.5 + 18 = 23.5