Answer:
81
Step-by-step explanation:
(9x - 4)(9x + 4) = ax² - b
81x² - 36x + 36x - 16
= 81x² - 16
=> a = 81
Answer:
The answer would be H for 30
Step-by-step explanation:
D.
This is because it is a question that involves doing actual math rather than just asking and getting an answer.
Answer:
Ps. don't show your link next time becuase if you look up sequin you get TEXAS. answer is 360
Step-by-step explanation:
multiply one at a time
Answer:
10c = 20
5c = 5
Step-by-step explanation:
Let x be the number of 10c coins; let y be the number of 5c coins. The total is $2.25, so the amount of 10c and 5c coins will add to that. Simita has 25 coins, so x and y, the number of coins, will have to add to 25. Hence, solve the simultaneous equation.
10x + 5y = 225 (1) - times by 0
x + y = 25 (2) - times by 5
10x + 5y = 225 (1)
5x + 5y = 125 (2)
Then, take equation 2 away from equation 1.
5x = 100
x = 20
Substitute x back into the original equation.
x + y = 25
20 + y = 25
y = 5
