Y=(x+5) (x+4) in vertex form of parabola

Step-by-step explanation:

The vertex form of an equation of a parabola y = ax² + bx + c:

(h, k) - verex

We have:

           use FOIL (a + b)(c + d) = ac + ad + bc + bd

a = 1, b = 9, c = 20

For k, put the value of h to the equation y = (x + 5)(x + 4):

Finally:

13

step-by-step explanation:

169-1=168

168-3=165

165-5=160

160-7=153

153-9=144

144-11=133

133-13=120

120-15=105

105-17=88

88-19=69

69-21=48

48-23=25

25-25=0

since it took 13times to completely subtract it hence its square root is 13