Solve for one of the variables in the first equation (in this case, I will solve for X):
X = Y + 3
Then use that value of X in the second equation to solve for Y:
X + 3Y = 9
(Y + 3) + 3Y = 9
4Y + 3 = 9
4Y = 6
Y = 1.5
Use the value of Y we just found in the X equation we created:
X = Y + 3
X = 1.5 + 3
X = 4.5
Therefore X = 4.5 or 9/2 and Y = 1.5 or 3/2.
300miles÷15=20
Efficient:20miles/gallons of gas
David purchased some cookies at the cost of
5 for $4 (5/4=1.25) and
sold them at 4 for $5(4/5=0.80).
To find cost per cookie subtract 1.25-0.80=0.45
David made a profit of $180 in total ( divide profit per cookie cost: 180/0.45= 400)
How many cookies did David purchase to make that much money?
He needed to make 400 cookie to make the profit of $180.
What line? try uploading an equation
Answer:
t1= -4
Given that result we must now find "n"