You add 13 and 8 it gets 21 so for X its 13
Answer:
90
Step-by-step explanation:
Start with changing 35% and 30% to a decimal.
35% = .35%
30% = .30%
Then multiply 105 by .30%. ( but don't put the percent sign in the calculator when multiplying)
105 x .30% = 31.5
Then you want to divide 31.5 by .35%
31.5 / .35% = 90
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.
Answer:
21
Step-by-step explanation:
i worked out the problem
Answer:
Step-by-step explanation: So, you need to add like terms. All the A's must be combined, all the B's and so on. Let's start with the A's. You have -7 (because there is a minus sign in front), and a 10. -7 + 10 gives you 3. That is where your 3a comes from.
Next, let's do the B's. You have 10, -1, and -9. It equals zero. So, you have no B's in the final answer.
You leave the singular 5 because you can't combine it with anything. So your final answer is 3a+5.
If you need any clarification or other help, please let me know!