Answer:
Step-by-step explanation:
We can let b and c represent the cost of a book and the cost of a CD, respectively. Then the purchases can be described by ...
3b +7c = 79
5b +2c = 35
Using Cramer's rule to find the solution, we have ...
b = (7(35)-2(79))/(7(5) -2(3)) = 87/29 = 3
c = (79(5)-35(3))/29 = 290/29 = 10
The cost of each book was $3; the cost of each CD was $10.
_____
Cramer's rule tells you the solution to ...
ax +by = c
dx +ey = g
is ...
x = (bg -ec)/(bd -ea)
y = (cd -ga)/(bd -ea) . . . . same denominator
This solution is fully equivalent to using elimination or substitution to solve the problem. Using these formulas effectively "cuts to the chase" without all the intermediate steps. The cross-multiplying pattern of differences is not hard to memorize.
Tan44°=x/140
x=135.19
x is the partial height of the pole after we exclude 4 feet tall height.
then add 4 to x=139.12 feet
Answer:
Aluno X
Step-by-step explanation:
A nota média para os alunos X e Y são, respectivamente:
A variância é definida pela seguinte expressão:
Onde n é o numero de termos, neste caso, n = 4.
As variâncias para cada aluno são:
O aluno X apresentou uma variância menor do que o aluno Y em suas notas e, portanto, apresentou ser o mais regular.
Answer:
6 small cubes
Step-by-step explanation:
given in cuboid made from 6 small cubes
Answer:
Will is 8 years old, Ben is 11 years old, and Jan is 22 years old
Step-by-step explanation:
Since Ben is 3 years older, his age can be represented by w + 3
Jan is twice as old as Ben, so her age can be represented by 2(w + 3)
Set up an equation that adds up these expressions and sets it equal to 41:
(w) + (w + 3) + 2(w + 3) = 41
Simplify, add like terms, and solve for w:
(w) + (w + 3) + 2(w + 3) = 41
(w) + (w + 3) + (2w + 6) = 41
4w + 9 = 41
4w = 32
w = 8
So, Will is 8 years old.
Find Ben's age by adding 3 to this:
8 + 3
= 11
Find Jan's age by multiplying this by 2:
11(2)
= 22
So, Will is 8 years old, Ben is 11 years old, and Jan is 22 years old
