Maths practice

1. Which is greater than 4?

(a) 5,

(b) -5,

(c) -1/2,

(d) -25.

Solution:

5 greater than 4.

Answer: (a)

2. Which is the smallest?

(a) -1,

(b) -1/2,

(c) 0,

(d) 3.

Solution:

The smallest number is -1.

Answer: (a)

3. Combine terms: 12a + 26b -4b – 16a.

(a) 4a + 22b,

(b) -28a + 30b,

(c) -4a + 22b,

(d) 28a + 30b.

Solution:

12a + 26b -4b – 16a.

= 12a – 16a + 26b – 4b.

= -4a + 22b.

Answer: (c)

4. Simplify: (4 – 5) – (13 – 18 + 2).

(a) -1,

(b) –2,

(c) 1,

(d) 2.

Solution:

(4 – 5) – (13 – 18 + 2).

= -1-(13+2-18).

= -1-(15-18).

= -1-(-3).

= -1+3.

= 2.

Answer: (d)

5. What is |-26|?

(a) -26,

(b) 26,

(c) 0,

(d) 1

Solution:

|-26|

= 26.

Answer: (b)

6. Multiply: (x – 4)(x + 5)

(a) x2 + 5x - 20,

(b) x2 - 4x - 20,

(c) x2 - x - 20,

(d) x2 + x - 20.

Solution:

(x – 4)(x + 5).

= x(x + 5) -4(x + 5).

= x2 + 5x – 4x – 20.

= x2 + x - 20.

Answer: (d)

7. Factor: 5x2 – 15x – 20.

(a) 5(x-4)(x+1),

(b) -2(x-4)(x+5),

(c) -5(x+4)(x-1),

(d) 5(x+4)(x+1).

Solution:

5x2 – 15x – 20.

= 5(x2 – 3x – 4).

= 5(x2 – 4x + x – 4).

= 5{x(x - 4) +1(x - 4)}.

= 5(x-4)(x+1).

Answer: (a).

8. Factor: 3y(x – 3) -2(x – 3).

(a) (x – 3)(x – 3),

(b) (x – 3)2,

(c) (x – 3)(3y – 2),

(d) 3y(x – 3).
Solution:

3y(x – 3) -2(x – 3).

= (x – 3)(3y – 2).

Answer: (c).

9. Solve for x: 2x – y = (3/4)x + 6.

(a) (y + 6)/5,

(b) 4(y + 6)/5,

(c) (y + 6),

(d) 4(y - 6)/5.

Solution:

2x – y = (3/4)x + 6.

or, 2x - (3/4)x = y + 6.

or, (8x -3x)/4 = y + 6.

or, 5x/4 = y + 6.

or, 5x = 4(y + 6).

or, 5x = 4y + 24.

or, x = (4y + 24)/5.

Therefore, x = 4(y + 6)/5.

Answer: (b).

10. Simplify:(4x2 - 2x) - (-5x2 - 8x).

Solution:

(4x2 - 2x) - (-5x2 - 8x)

= 4x2 - 2x + 5x2 + 8x.

= 4x2 + 5x2 - 2x + 8x.

= 9x2 + 6x.

= 3x(3x + 2).

Answer: 3x(3x + 2)