2. which of the following proves that 209 is not a prime number? a) 209 × 1 = 209 b) 19 × 11 = 209 c) 209 is an odd number d) 209 is not visible by 2,3,5 and 7.

the answer is B) 19 × 11 = 209

coz A prime number is a whole number greater than 1 whose only factors are 1 and itself.

but here it is a multiple of 11 and 19

so its proved

answer: standard form is ax^2 + bx + c = 0

step-by-step explanation:

standard form is ax^2 + bx + c = 0

(2x + 1)(x - 2) = 0

distribute to get into standard form

2x^2 - 4x + x - 2 = 0

2x^2 - 3x - 2 = 0

a = 2, b= -3, c = -2

a is your answer

first, you divide the triangle in two, tô form a retangle triangle. after, using pythagoream theorem:

18^2 = 14^2 + (x/2)^2

(x^2/4) + 196 = 324

x^2/4 = 324 - 196

x^2/4 = 128

x^2 = 512

x = √512

x = √2^9

x = 16√2 cm

i hope i you.