Forming equations

Question 1

Form a linear equation from the following statement

John is x years old. His brother is y years old. Their total age is 40

Answer 1

x + y = 40

Total means add

Question 2

Form a linear equation from the following statement

John is x years old. His brother is 2y years old. The sum of their age is 50

Answer 2

x + 2y = 50

‘The sum of’ means add

Question 3

Form a linear equation from the following statement

John is x years old. His younger brother is y years old. The difference in their age is 20

Answer 3

x - y = 10

‘difference ‘ means minus

Since John is older, x should be to the left

Question 4

Form a linear equation from the following statement

The length of a rectangle is x cm. The breadth is y cm. The perimeter is 80 cm

Answer 4

2x + 2y = 80

‘perimeter’ is the sum of the sides

You multiply each term by 2, and there are 2 lengths and breadths.