Answer: 120 individual tacos
Step-by-step explanation: So this problem can be represented by the two equations T + E = 300. (T for tacos E for enchiladas) and the equation 2T + 3E = 780. For simplicity I'm going to place these on top of each other.
T + E = 300
2T + 3E = 780
We want to plug one equation into the other so I will solve for E in the first equation.
T - T + E = 300 - T
E = 300 -T
Now we have a value of E that can be plugged into our second equation so let's do that
2T + 3(300 - T) = 780 then we multiply this out.
2T + 900 - 3T = 780
-T + 900 - 900 = 780 - 900
-1 • -T = -120 • -1
T = 120 tacos sold
We can check this by plugging in our values into our equations
300 - 120 = 180 enchiladas sold
2(120) + 3(180) = $780.
Please comment if you have any questions.
