Answer: P=130
2W +2L=130
2(31) + 2(34)=130
W=31
L=34
Step-by-step explanation:
P=130
2L + 2W
W=L-3
Add all of the sides together to get perimeter.
2(L-3) + 2L=130
2L-6+2L=130
4L-6+6=130+6
4L=136
4L/4=136/4
L=34
W=L-3
W=34-3
W=31
The general way to work this out is to solve the general expression for
the remaining quantity versus half-life, using logarithms. But that's not
necessary with these numbers.
Look at the numbers:
-- 3 mg is 1/4 of 12 mg.
-- 1/4 is the product of (1/2) x (1/2).
-- So the 3 mg is what's left of 12 mg after 2 half-lives.
The 26 minutes must be two half-lives.
-- The half-life of that substance is 26/2 = <em>13 minutes</em>.
Go Maggie !
One positive and one negative
Answer:
The coordinates of 
are 
and 
.
Step-by-step explanation:
Let be 
and 
endpoints of segment AB and a point located 7/10 the way from A to B. Vectorially, we get this formula:
By Linear Algebra we get the location of :
If we know that 
and 
, then:
The coordinates of are and .
Answer:
x = 13.4
Step-by-step explanation:
Use the Pythagorean Theorem
a² + b² = c²
x² + 6.8² = 14.1²
x² = 14.1² - 6.8²
x² = 152.57
Take the square root of both sides
x = 12.3519229272
Rounded
x = 13.4
