Lesson 4️⃣ Further Substitution

Question 1

If a=-2 b=3 evaluate the following expression

a²

Answer 1

a x a
(-2) x (-2)
=4

Question 2

If a=-2 b=3 evaluate the following expression

1-b²

Answer 2

1 - b x b
1 - 3 x 3
1 - 9
= -8

Question 3

If a=-2 b=3 evaluate the following expression

2a²

Answer 3

2 x a²
2 x (-2) x (-2)
2 x 4
=8

Question 4

If a=-2 b=3 evaluate the following expression

(2a)²

Answer 4

(2 x - 2)²
(-4)²
= -16

Question 5

If a=-2 b=3 evaluate the following expression

(3a)² - 2b²

Answer 5

(3a)² = (3 x -2)²
=(-6)² = 36

2b²=2x3²
=2x9
=18

(36-18=18)

Question 6

If a=-2 b=3 evaluate the following expression

a³- 4b

Answer 6

a³ = (-2) x (-2) x (-2)
=-8
4b = 4 x 3 = 12
-8 -12 = -20

Question 7

If a=-2 b=3 evaluate the following expression

a²- ab

Answer 7

x² = (-2) x (-2)
=4
ab = -2 x 3
= -6
4-(-6
=10

Question 8

If a=-2 b=3 evaluate the following expression

(2ab)² + 2ab²

Answer 8

(2ab)²= (2 x -2 x 3)²
(-12)²
=144

2ab² = 2 x (-2) x 3²
= -4 x 9
= -36
144 + (-36)
144 - 36
= 108