Answer:
Rachel bought 5 cups of coffee (x = 5) and 2 cups of black tea (y = 2).
Explanation:
Let's assume Rachel bought x cups of coffee and y cups of black tea. According to the given information, the cost of a cup of coffee is $4, and the cost of a cup of black tea is $3. We can set up the following equations based on the total cost:4x + 3y = 26 ---(1) (Total cost equation)
x + y = 7 ---(2) (Total number of drinks equation)To solve this system of equations, we can use substitution or elimination method. Let's use the elimination method to solve the equations: Multiply equation (2) by 3 to make the coefficients of y in both equations equal:3(x + y) = 3(7)
3x + 3y = 21 ---(3)Now, subtract equation (3) from equation (1) to eliminate y:4x + 3y - (3x + 3y) = 26 - 21
4x + 3y - 3x - 3y = 5
x = 5Substitute the value of x = 5 into equation (2) to find y:5 + y = 7
y = 7 - 5
y = 2