MATH REVISION

3√6 + 4√6 is equal to:

• 6√6

• 7√6

• 4√12

• 7√12

Answer explanation

3√6 + 4√6 = (3 + 4)√6 = 7√6

The number obtained on rationalising the denominator of 1/ (√7 – 2) is

• (√7+2)/3

• (√7-2)/3

• (√7+2)/5

• (√7+2)/45

One of the linear factors of 3x²+8x+5 is

• (x-4)

• (x+2)

• (x-2)

• (x+1)

Answer explanation

3x²+8x+5 = 3x²+ 3x+5x+5 

3x²+8x+5 = 3x(x+1)+5(x+1)

3x²+8x+5 = (3x+5)(x+1)

Therefore, (x+1) is one of the factors of 3x²+8x+5.

If the perpendicular distance of a point P from the x-axis is 7 units and the foot of the perpendicular lies on the negative direction of x-axis, then the point P has:

• y-coordinate = 7 or –7 only

• y-coordinate = 7 only

• y-coordinate = –7 only

• x-coordinate = –7

Abscissa of all the points on the x-axis is

• 0

• 1

• 2

• ANY NUMBER

The linear equation 3x-11y=10 has:

• Unique solution

• Two solutions

• Infinitely many solutions

• No solutions

Find the value of k, if x = 1, y = 2 is a solution of the equation 2x + 3y = k.

• 5

• 6

• 7

• 8

Answer explanation

2x + 3y = k

k=2(1)+3(2) = 2+6 = 8

If we multiply or divide both sides of a linear equation with the same non-zero number, then the solution of the linear equation:

• Changes in case of multiplication only

• Changes in case of division only

• Remains the same

• changes both sides

If AB || CD, EF ⊥ CD and ∠AGE = 135° as per the figure given below. The value of ∠GEF is:

• 120°

• 45°

• 90°

• 135°

If two interior angles on the same side of a transversal intersecting two parallel lines are in the ratio 2 : 3, then the greater of the two angles is:

• 54°

• 108°

• 120°

• 136°

Answer explanation

2x+3x = 180°

5x = 180°

x = 180°/5 = 36°

Hence, 3x >2x. It means ∠2 >∠1

The value of ∠2 = 3(36°) = 108°