21x-9+63=180
21x+54=180
21x=126
x=6
Answer:
the simplified expression is 32/ 81
Answer:
x=11
Step-by-step explanation:
34(RT) minus 12(RS)=22. 22 divided by 2 equals 11.
The best way to multiply complicated problems mentally* is to break them into chunks.
Start with 20 times 8 to get 160, and then 8 times 5 to get 40. Add these together to get 200. 200 times 3 is 600, and 20 times 200 is 4000. Add these together to get your final answer, 4600.
In other words 8 x 20 + 8 x 5 = 200 200 x 3 + 200 x 20 = 4600
*I assumed you meant mentally, because otherwise you'd just multiply longhand, multiplying two of the three numbers and then multiplying their product with the third.
Short leg = 18 Long leg= 24 Hypotenuse= 30
My calculations were simple trial and error. I started with a trial of 10 for the short leg to begin with, averaging and estimating the appropriate proportions based off 6 additional increments. Sorry I don't have an algebraic method for you. Hope this has helped somewhat :)
