Joel = j, Mark = m, Sandra = s
j + m + s = 120
m = 3j
j = 1/2 s --> s = 2j
plug in (substitute) each letter to make it in terms of only j: j + m + s = 120
j + 3j + 2j = 120
6j = 120
6j/6 = 120/6
j = 20
now plug in for the j & s equation:
s = 2j = 2(20) = 40
Therefore Sandra has 40 coins!
Answer: 1725 ft^2
Step-by-step explanation:
Rectangle part is 30*50 or l*w = 1500
Triangle is 15*30/2=225
Add the two to get area
1500+225=1725
Answer:
C
Step-by-step explanation:
Given
+
← factor the denominator of first fraction
=
+ 
Multiply the numerator/ denominator of second fraction by (x + 2)
=
+ 
The denominators are now common, so add the numerators leaving the denominator, that is
= 
=
→ with numerator 4x + 6 → C
Answer:
8.8 cm
Step-by-step explanation:
-We know that the top 20% of the books are oversized.
-We therefore find the z-value of the top 20%:

#We substitute the z value in formula to solve X.

Where
- X is the minimum thickness of the book.
-Given
, the minimum thickness,X can be calculated as follows:

Hence, the minimum thickness of the oversized books is 8.8 cm