In triangle ABC, EF=

a) 3cm
b) 2.5cm
c) 4cm
d) none of these

AE/AB = EF/BC

4cm/ 8cm = EF/ 5cm(Criss cross)

EF = 5 x 4/8

EF = 2.5 cm

-14

step-by-step explanation:

2x2 – 2(x+4)

=2x2-2（5+4）

=4-2×9

=4-18

=-14

none of the above.

for one of the equations to be used in the process, there has to be a term in the equation since squared is .

since there is only a term in the first equation, we cannot derive a from completing the square.

solving with completing the square