Answer:
Step-by-step explanation:
Note that one equation has -2y and the other has +2y. The fastest solution is to add the equations together. The two terms will cancel out, eliminating the y terms.
100-30=70-50=20
there's your equation
Answer:
a) 4 people ordered streak dinner
b) 3 people ordered chicken dinner
Step-by-step explanation:
Let the number of people that ordered steak dinner be x
and the number of people that ordered chicken dinner be y
From the question,
There are 7 people in your family
Hence, we can write that
x + y = 7 ...... (1)
Also from the question
Some order the chicken dinner for $13 and some order the steak dinner for $18 and the total bill was $111.
We can then write that
13y + 18x = 111 ...... (2)
From equation (1)
x + y = 7
Then,
x = 7 - y ...... (3)
Put this into equation (2)
13y + 18x = 111
13y + 18(7 - y) = 111
13y + 126 - 18y = 111
-5y = -15
5y = 15
y = 15 / 5
y = 3
Put the value of y into equation (3) to get x
x = 7 - y
Then
x = 7 - 3
x = 4
Hence, 4 people ordered streak dinner
and 3 people ordered chicken dinner
a) 4 people ordered streak dinner
b) 3 people ordered chicken dinner
