y = x³ + 3x² - x - 3
0 = x³ + 3x² - x - 3
0 = x²(x) + x²(3) - 1(x) - 1(3)
0 = x²(x + 3) - 1(x + 3)
0 = (x² - 1)(x + 3)
0 = (x² + x - x - 1)(x + 3)
0 = (x(x) + x(1) - 1(x) - 1(1))(x + 3)
0 = (x(x + 1) - 1(x + 1))(x + 3)
0 = (x - 1)(x + 1)(x + 3)
0 = x - 1 or 0 = x + 1 or 0 = x + 3
+ 1 + 1 - 1 - 1 - 3 - 3
1 = x or -1 = x or -3 = x
Solution Set: {-3, -1, 1}
1. 7+ (-9) = 7-9=-2
2.(-8) + (+5)= -8+5= -(8-5)=-3
3.(+9) - (-3) = 9+3=12
4.(+12) - (-1) = 12+1=13
5. (-7) - (-5) = -7+5==(7-5)=-2
<span>(-14) - (+2) = -14-2=-(14+2)=-16</span>
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)
What do I solve? We need more info