Answer:
Number of batches of cookies = 4
Number of batches of brownies = 7
Step-by-step explanation:
Let the number of batches of cookies she made = x
And the number of batches of brownies = y
Total number of batches she made = 11
So the equation representing batches will be,
x + y = 11 ---------(1)
Her recipe for cookies calls for eggs = 1 per batch
So eggs required for x batches of cookies = 1 × x = x
Similarly, her recipe for brownies calls for eggs = 2 per batch
So, eggs required for y batches of brownies = 2y
Total number of eggs required = 18
Therefore, equation will be,
x + 2y = 18 ---------- (2)
Equation (2) minus equation (1)
(x + 2y) - (x + y) = 18 - 11
y = 7
From equation (1),
x + 7 = 11
x = 4
Therefore, number of batches of cookies and brownies she made were 4 and 7.