Let's say this number is a:
a*(a-9) = 90
a^2-9a-90 = 0
(a-15)(a+6) = 0
a = 15 or a = -6
Therefor a. would be the correct answer :)
Answer:
ST = 12 units
Step-by-step explanation:
As RA is parallel to ET, the angle in R is equal to the angle in T, and the angle in A is equal to the angle in E, so the triangle RAS is similar to the triangle SET.
If RT is 21 units, we have that RS + ST = 21 -> RS = 21 - ST
Using a rule of three with the sides of the triangle (as they are proportional), we have:
RS / ST = AR / ET
(21 - ST) / ST = 6 / 8
4 * (21 - ST) = 3*ST
84 - 4*ST = 3*ST
7*ST = 84
ST = 12 units
I hope this helps .......
It's the decimals but you did a reciprocal
I think it might be division because when we have to decide something Into something, we have to always divide. I hope I m right!
