Given that fx 5x2 50x 123 15 has a squareroot at x 4 25

Given that f(x) = 5x^2 + 50x + 123 1/5 has a squareroot at x = -4 2/5, use the axis of symmetry to find the other squareroot of the function. Solve 5w^2 - 4w = -2 3/5 by completing the square. Simplify each expression (write any complex answers in standard form). (7 + i) + (4 - 3i) (-3 -4i) - (-4 -(-3) i) (6 - 2i)(-4 + 5i) 7 - 3i/-2 - 5i

Solution

13. ( 7 + i ) + ( 4 - 3i )

= 10 - 2i

14. ( -3 - 4i) - (-4 - (-3)i)

= -3 -4i +4 -3i

= 1 - 7i

15. ( 6 - 2i )( -4 + 5i)

= 6*(-4) +6*5i -2i*(-4) -2i*(5i)

= -24 + 30i + 8i - 10i²

= -24 + 38i +10

= -14 + 38i

16. ( 7 - 3i )/ ( -2 - 5i)

=  ( 7 - 3i )/ ( -2 - 5i)*( -2 + 5i)/( -2 +5i)

= (-14 + 35i + 6i - 15i²) / (4 + 25)

= ( -14 + 41i +15)/29

= ( 1 + 41i)/29

= 1/29 + 41i/29