Translate into equations - Summative revision

The sum of two consecutive integers is 39.

• x + (x + 1) = 39

• x + (x + 2) = 39

• x - (x + 2) = 39

The sum of two consecutive even integers is 38.

• x + (x + 1) = 38

• x + (x + 2) = 38

• x + 2 = 38

• x = 38

The sum of two consecutive odd integers is 72.

• x + (x + 2) = 72

• x + 2 = 72

• x = 72

• x + (x + 1) = 72

The sum of 3 consecutive integers is 15.

• x + x + x = 15

• x + 2x + 3x = 15

• x + (x + 1) + (x + 2) = 15

• x = 15

A number is doubled and 5 is added. The result is 21.

• x + 21 = 5

• 2x = 21

• 2x + 5 = 21

• x + 5 = 21

A number is increased by 10 and the resulting number is doubled. The answer is 20.

• 2x = 10

• x + 10 = 20

• 2x + 10 = 20

When a number is increased by 5, the answer is 11.

• x = 11

• x + 5 = 11

• x + 11 = 5

• 5 + 6 = x

When a number is decreased by 7, the answer is 20.

• x - 7 = 20

• x - 20 = 7

• x = 20

• 20 = 7

Four more than six times a number is 18.

• 10x = 18
• 4x + 6 = 18
• 4 + 6x = 18

349 is the sum of a and 311

• a = 311

• a + 349 = 311

• a + 311 = 349

• a = 349