Answer:
The first one, the third one, and the fourth one.
Step-by-step explanation:
i just put the ones that are correct. If you want me to write out why the incorrect ones are incorrect, let me know.
1.
-6=3x
-6= 3(-2)
-6= -6
3. -8= x+x+x+x
-8= -2+-2+-2+-2
-8= -8
4. x/2= (-1)
-2/2 =(-1)
-1= -1
Answer:
y – 8 = –0.2(x + 10)
Step-by-step explanation:
Answer:
(1,-1)
Step-by-step explanation:
We can solve the system by using substitution.
In order to do this we must make x the subject in the first equation.
We can do this by simply subtract 2y from both sides
x + 2y = -1
subtract 2y from both sides
x + 2y - 2y = -1 - 2y
simplify
x = -2y - 1
now that we have made x the subject in one of the equations we can plug in (or substitute) the value of x into the other equation
2x – 3y = 5
x = -2y - 1
2(-2y - 1) - 3y = 5
We can then solve for y
2(-2y - 1) - 3y = 5
Distribute the 2
-4y - 2 - 3y = 5
combine like terms -4y + -3y
-7y - 2 = 5
add 2 to both sides
-7y = 7
divide both sides by -7
y = -1
Now that we have found the value of y we can plug in the value of y into one of the equations and solve for x
x + 2y = -1
y = - 1
x + 2(-1) = -1
multiply 2 and -1
x + -2 = -1
add 2 to both sides
x = 1
So we have found that x = 1 and y = -1 therefore the solution to the system of equations is (1,-1)
Answer:
Step-by-step explanation:
Let x = the number of $20 bills.
Then x + 6 = the number of $5 bills and
20x + 5(x + 6) = 455
x = 17 = number of $20 bills
x + 6 = 17 + 6 = 23 = number of $5 bills
Check:
OK.
