Answer:
3 + 4 = 7 which is true.
Step-by-step explanation:
Whenever you have an equation with a plain variable (that is, no exponent included), there is only one number that will work when substituted for x.
To solve it, you have to "undo" what is done to the variable. You also go in the reverse order of operations, so you do the addition/subtract first, then multiplication/division.
You also have to do the same to both sides, kind of like keeping a balance scale in balance.
In this case, we subtract 4 from both sides first:
3x + 4 -4 = 7 - 4
The + 4 - 4 cancel each other out, so you get:
3x = 3
3x means "3 times x" so you divide by 3 to undo it. I will use the / to indicate division:
3x / 3 = 3 /3
so 1x = 1.
Since 1x is "1 times x" it is the same as x by itself, so:
x=1
AND, if we substitute 1 back into the original equation (the asterisk stands for multiply):
3 * 1 + 4 = 7
3 * 1 is 3, so:
3 + 4 = 7 which is true.
1 is the only number that works.
Hope this helped.
Answer:
3.93 per hour
Step-by-step explanation:
The first 4 hours is at 20 hours / 4 hours or 5 dollars an hours
The second line has a slope of 2.50 dollars an hour
But there is also a surcharge when you go over 4 hours
That is a 5 dollar flat rate at 4 hours
Assuming that we do not include the flat rate in the hourly calculation
4 hours * 5 dollar + 3 hours * 2.50 = 20+7.50
27.50 is the hourly charge
Divide by 7 hours
3.928571429
3.93 per hour
Alright, as we can see the large rectangle's area is 4x² + 9x + 2.
You can also see that gray rectangle's area inside the larger rectangle is
x² + 4x + 3.
So if we want to find the white area in-between the two rectangles we will need to SUBTRACT the two formulas! (Subtract the large rectangle from the smaller one)
To do so we will need to subtract the like terms.
The like terms are 4x² and x², 9x and 4x, 2 and 3!
So first we do 4x² - x² and you get 3x²
Next, we do 9x - 4x and you get 5x
Lastly, we do 2 - 3 and you get -1
Now we put our solutions together and you get...
3x² + 5x - 1
This is the are for the white region of your problem. :D glad to help
Answer: D. The moon is located perpendicular to Earth and the sun.
Step-by-step explanation: I studied astronomy. :)
Answer:
x<120
Step-by-step explanation:
-30<x/-4
In order to simplify this, we must isolate the x value by multiplying both sides by -4
Since we are dealing with inequalities and we are multiplying by a negative number, we have to switch the sign (<,>)
-30(-4)>x
x<120
