Answer: a) 6 j + 10 w = 15.20, 1 j + 2 w = 2.90 is the required system of the equations.
b) The solution is j = $0.7 and w = $ 1.1
c) $1.8 is the bill be for 1 glass of apple juice and 1 waffle.
Explanation:
Since here j stand for the price of a glass of juice and w stand for the price of a waffle special.
And According to the question,
The bill for the family special of 6 glasses of apple juice and 10 waffles specials is $15.20,
That is, 6 j + 10 w = 15.20 ------ (1)
And, The bill for 1 glass of apple juice and 2 waffles specials is $2.90.
That is, 1 j + 2 w = 2.90 ------ (2)
Since, In substitution method we find the solution by substituting the value of one variable from one equation to other equation,
By equation (2), j = 2.90 - 2 w -----(3)
Put this value of j in equation (1),
We get, 17.4 - 12 w + 10 w = 15.20
⇒ 17.4 - 2 w = 15.20
⇒ 2 w = 2.2
⇒ w = 1.1
Put this value in equation (3),
we get, j = 2.90 - 2×1.1 = 2.90 - 2.2 = 0.7
⇒ j = 0.7
Thus, the cost of one glass of apple juice = $ 0.7
And, the cost of one waffles = $ 1.1
Thus, the bill be for 1 glass of apple juice and 1 waffle = 0.7 + 1.1 = $1.8