Linear Equations in One Variable — Chapter Test | Class 8 IMO

Q1

To solve 2x + 3 = 11, you first subtract ___ ?

Subtracting 3 gives 2x = 8.

Q2

3x = x + 8 means 2x = 8, so x = ___ ?

x = 8 ÷ 2 = 4.

Q3

If 2x = 10 gives x = 5, then 4x = 20 gives x = ___ ?

x = 20 ÷ 4 = 5.

Q4

Write 'twice a number minus 3' as an expression.

Twice a number is 2x, minus 3.

Q5

Solve: 2x + 3 = x + 8.

x = 8 − 3 = 5.

Q6

Solve: 3(x − 2) = 9.

3x − 6 = 9, so x = 5.

Q7

Solve: 5x = 2x + 12.

3x = 12, so x = 4.

Q8

Solve: x/2 + x/3 = 5.

Multiply by 6: 5x = 30, so x = 6.

Q9

Solve: (x + 1)/2 = 4.

x + 1 = 8, so x = 7.

Q10

Solve: 4x − 7 = 2x + 5.

2x = 12, so x = 6.

Q11

Three consecutive integers add up to 27. The smallest is ___ ?

3n + 3 = 27, so n = 8.

Q12

A father is three times as old as his son and 30 years older. The son's age is ___ ?

x + 30 = 3x, so x = 15.

Q13

Solve: 2(x + 3) = 3(x − 1).

2x + 6 = 3x − 3, so x = 9.

Q14

A rectangle has perimeter 30 cm and length twice the breadth. The breadth is ___ ?

2(2b + b) = 30, so 6b = 30 and b = 5 cm.