Answer: 225 altogether.
Explanation:
Let x represent Meihua's number and y represent Maria's number of books.
4x = y and x + 135 = y
Substitute and solve for x
4x = x + 135 Subtract x from both sides.
3x = 135. Divide both sides by 3.
x = 45 That's how many Meihua has. Then figure Maria's number by substituting 45 in place of x in the original equations.
4(45) = y. And 45 + 135 = y
In both, y = 180.
x + y = total altogether
45 + 180 = 225