Answer:
<h3>x = -2</h3>
Step-by-step explanation:
![3[-x + (2 x + 1)] = x -1\\\\\mathrm{Expand\:}3\left(-x+\left(2x+1\right)\right):\quad 3x+3\\3x+3=x-1\\](https://tex.z-dn.net/?f=3%5B-x%20%2B%20%282%20x%20%2B%201%29%5D%20%3D%20x%20-1%5C%5C%5C%5C%5Cmathrm%7BExpand%5C%3A%7D3%5Cleft%28-x%2B%5Cleft%282x%2B1%5Cright%29%5Cright%29%3A%5Cquad%203x%2B3%5C%5C3x%2B3%3Dx-1%5C%5C)
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The answer to this question is : <span>Megohm meter</span>
Answer:
A
Step-by-step explanation:
Since the triangle is right use Pythagoras' identity to find EF
The square on the hypotenuse is equal to the sum of the squares on the other two sides, that is
EF² + DF² = DE² ← substitute values
EF² + 12² = 18², that is
EF² + 144 = 324 ( subtract 144 from both sides )
EF² = 180 ( take the square root of both sides )
EF = 
→ A
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.
