Hmm if I'm not mistaken, is just an "ordinary" annuity, thus
![\bf \qquad \qquad \textit{Future Value of an ordinary annuity} \\\\ A=pymnt\left[ \cfrac{\left( 1+\frac{r}{n} \right)^{nt}-1}{\frac{r}{n}} \right] \\\\\\](https://tex.z-dn.net/?f=%5Cbf%20%5Cqquad%20%5Cqquad%20%5Ctextit%7BFuture%20Value%20of%20an%20ordinary%20annuity%7D%0A%5C%5C%5C%5C%0AA%3Dpymnt%5Cleft%5B%20%5Ccfrac%7B%5Cleft%28%201%2B%5Cfrac%7Br%7D%7Bn%7D%20%5Cright%29%5E%7Bnt%7D-1%7D%7B%5Cfrac%7Br%7D%7Bn%7D%7D%20%5Cright%5D%0A%5C%5C%5C%5C%5C%5C)
So you make your equation 4x+20+40=180.
Add like terms and get 4x+60=180.
Subtract 60 from both sides, get 4x=120.
Divide boths sides by 4, get your answer of x=30.
Hope this helps
Answer:
B. 30
Step-by-step explanation:
Boys to girls
2 : 3
Units of girls = 3
3 units = 18
1 unit = 18 ÷ 3 = 6
Total number of units = 2 + 3 = 5
5 units = 6 x 5 = 30
Answer:
100:9
Step-by-step explanation:
If corresponding side lengths are in the ratio 10 : 3, the ratio of their areas will simply be the square (area is 2-dimensional).
Therefore:
10 : 3 ⇒ (10)² : (9)²
100 : 9 is the ratio of the areas.
hope this helps :)