Answer:
12=12
Step-by-step explanation:
2a = b
a -3b =12
To solve, set one of the equations equal to zero. The first equation is actually already set to 0.
b = 2a
Now you can plug this equation into the other one, by substituting the b in the equation with this.
a -3b = 12
a – 3(2a) = 12
Now all you have to do is distribute the 3 (multiply the number outside the parenthesis, 3 in this case, by everything inside).
a – 6a = 12
Combine like terms. Since we have 1 positive a and 6 negative ones, we subtract the two numbers without the signs
6-1 = 5
And take the sign of the larger number. Since 6 is large and 6 is negative, we are left with
-5a = 12
Now solve for a, which in this case means dividing both sides by -5
a = -12/5
Simplify
a = -2.4
Now that you have a, it’s easy to find b
b = 2a
b = 2(-2.4)
b= -4.8
Now you check your work by plugging your new a and b into either equation to see if it’s true.
-4.8 = 2(-2.4)
-4.8 = -4.8
And just for laughs let’s try the other equation
a -3b =12
-2.4 – 3(-4.8) = 12
Distribute the 3 again. Remember that when two negative numbers are multiplied they become positive.
-2.4 +14.4 = 12
12 = 12
Answer:
I think it is +2. I hope this helps.!
Step-by-step explanation:
Answer:
Step-by-step explanation:
We can use the point-slope form given by:
Where <em>m</em> is the slope and (x₁, y₁) is a point.
So, we will substitute -2 for <em>m</em> and (5, 2) for (x₁, y₁). This gives us:
Simplify:
Distribute:
Add 2 to both sides. Hence, our equation is:
Answer:
The scaled surface area of a square pyramid to the original surface area.
The scaled area of a triangle to the original area.
Step-by-step explanation:
Suppose that we have a cube with sidelength M.
if we rescale this measure with a scale factor 8, we get 8*M
Now, if previously the area of one side was of order M^2, with the rescaled measure the area will be something like (8*M)^2 = 64*M^2
This means that the ratio of the surfaces/areas will be 64.
(and will be the same for a pyramid, a rectangle, etc)
Then the correct options will be the ones related to surfaces, that are:
The scaled surface area of a square pyramid to the original surface area.
The scaled area of a triangle to the original area.
We need to call for x minute
+ Phone Company A charges a monthly fee of $42.50, and $0.02 for each minute talk time. So we have to spend: <span>$42.50+ $0.02x
+ </span>Phone company B charges a monthly fee of $25.00, and $0.09 for each minute of talk time. So we have to spend: <span>$25.00+ $0.09x
We solve for x: </span>$42.50+ $0.02x> <span>$25.00+ $0.09x
or </span>$42.50- $25.00 > $0.09x- <span>$0.02x
and we have $0.07x<$27.50
or x< 27.50:0.07 and x< 393.86
The answer is:
If we have to call much time, at least 394 minutes, we should choose A
If not, choose B</span>
