The answer is y=10/7-5/7x, subtract the 5x and put it on the other side then divide the 7 from the y and divide it to 10-5x to get the answer.
Answer:
C
Step-by-step explanation:
Let <em>a</em> and <em>b</em> be the two numbers. Then
<em>a</em> + <em>b</em> = -4
<em>a b</em> = -2
Solve the second equation for <em>b</em> :
<em>b</em> = -2/<em>a</em>
Substitute this into the first equation:
<em>a</em> - 2/<em>a</em> = -4
Multiply both sides by <em>a</em> :
<em>a</em>² - 2 = -4<em>a</em>
Move 4<em>a</em> to the left side:
<em>a</em>² + 4<em>a</em> - 2 = 0
Use the quadratic formula to solve for <em>a</em> :
<em>a</em> = (-4 ± √(4² - 4(-2))) / 2
<em>a</em> = -2 ± √6
If <em>a</em> = -2 + √6, then
-2 + √6 + <em>b</em> = -4
<em>b</em> = -2 - √6
In the other case, we end up with the same numbers, but <em>a</em> and <em>b</em> are swapped.
Solution: For finding QR we need to apply Pythagoras Theorem
What is Pythagoras Theorem ?
ans : Pythagoras Theorem is the sum of square of two sides which is equal to the third side or the hypotenuse. This formula is valid oy incase of Right-Angled Traingle because one of three angles here is 90°
According to this law let's apply it in the diagram shown here.
- (Hypotenuse)² = (Adjacent)² + (Opposite)²
- (5x - 2)² = (QR)² + (3x - 1)²
- (QR)² = (5x - 2)² - (3x - 1)²
After factorising both of them we get
- (QR)² = 25x² - 20x + 4 - (9x² - 6x + 1)
- (QR)² = 25x² - 20x + 4 - 9x² + 6x - 1
So, QR is √(16x² - 14x + 3)
