Question

B. Using your answer in letter a or write the equation of the line in the form Ax + By = C​

Answer 1

Weight increasing for every weak

= Weight in week 2 - weight in week 1

= 9 - 5½ = 3½ kg

Weight in week 1 = 5½ kg

Weight in week 2 = 5½ + 3½ = 9 kg

Weight in week 3 = 9 + 3½ = 12½ kg

Weight in week 4 = 12½ + 3½ = 16 kg

Weight in week 5 = 16 + 3½ = 19½ kg

Answer 2

Solution :-

★ According to statement

Number of weeks is denoted by 'x' and quantity consumed in kg is denoted by 'y'.

Now, number of weeks and quantity consumed satisfy the linear relationship.

So, Let y = mx + c, .................(1)

where m and c are real constants.

★According to given condition,

Quantity consumed in 1st week = 5.5 kg

So, put x = 1 and y = 5.5 in (1), we get

⇛ 5.5 = m + c ........(2)

Also, quantity consumed in 2nd week = 9 kg

So, put x = 2 and y = 9 in (1), we get

⇛ 9 = 2m + c ...........(3)

Now, Subtract (1) from (2), we get

⇛ 3.5 = m ......(4)

Put value of m in (2), we get

⇛5.5 = 3.5 + c

⇛ c = 2

So, equation (1) can be rewritten as

y = 3.5 x + 2

⇛ To get consumption in 3rd week, put x = 3, we get

⇛ y = 3.5 × 3 + 2 = 12.5

⇛ To get consumption in 4th week, put x = 4 we get

⇛ y = 3.5 × 4 + 2 = 16

⇛ To get consumption in 5th week, put x = 5, we get

⇛ y = 3.5 × 5 + 2 = 19.5

And equation of line is 3.5 x - y + 2 = 0.