The side opposite the 30o angle is 1/2 W. That is just a property of a 30 - 60 - 90 triangle. Use that fact to set up the pythagorean relationship.
w^2 = (1/2 w)^2 + (7 * sqrt(3)) ^2
w^2 = 1/4 w^2 + 49*3
w^2 = 1/4 w^2 + 147
3/4 w^2 = 147
w^2 = 147 * 4/3
w^2 = 49 * 4 = 196
w = sqrt (196)
w = 14
You have to multiply 1/4 by something so you can get to the number that is telling you to draw.
-x^2+2x+3=x^2-2x+3 add x^2 to both sides
2x+3=2x^2-2x+3 subtract 2x from both sides
3=2x^2-4x+3 subtract 3 from both sides
2x^2-4x=0 factor
2x(x-2)=0
So x=0 and 2
Answer:
Here is a way one of my math teachers taught me.
For + x + = +:
In elementary school, you were taught by your math teacher that an positive number multiplied with a positive number is equal to a positive number. To solve, use basic rules of multiplications.
For + x - = -:
Think of it this way. There are two line segments that makes a positive sign. When multiplying, you are subtracting a line, which would result in a negative sign. Whenever a positive multiplies a negative, it is always a negative outcome.
For - x - = +:
There are two lines given (two negatives). When multiplied, the two lines make a positive sign (which is made by drawing two lines). This shows that two negative numbers multiplied or divided together will make a positive sign .
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