Solve the system of equations.
12x + 3y = 12
-6x +y = -26
A) (-3,9)
B (-6, -9)
© (-3,8)
D (3, -8)
12x + 3y = 12
2(-6x +y = -26)
12x + 3y = 12
-12x + 2y = -52
—-now x cancels out
5y/5 = -40/5
y = -8
The answer should be D. Let me know if you got it right.
In the default window of a graphing calculator, there is only one intersection that you see.
However, if you zoom out, you will see that they are 3 intersections to the pair of equations.
Let the cost of the soft drink = C then the price of the sandwich was 3.5 times as much = 3.5C
And
C + 3.5C = Total Cost
C + 3.5C = 9
4.5C = 9 divide both sides by 4.5
C = 9/4.5 = $2.00 for the soft drink
And 3.5C = 3.5(2.00) = $7.00 cost of the sandwich
