Question

am nevoie de ajutor urgent ​

Answer 1

Explicație pas cu pas:

ex14

x+1/x=7

aducem la numitor comun

x²/x=7

simplificam x

x=7

calculam

7²+1/7²=49+1/49=49

ex 15

2(a-b+c)

ex 16

3(x³+2x²-4x+8)

ex 17

4x(x+3)+9

ex 18

3x(x-4y)+4y(4y-3x)

ex 19

x⁴-81=(x²+9)(x²-9)=(x²+9)(x+3)(x-3)

ex 20

16x⁴-1=(4x²-1)(4x²+1)=(4x²+1)(2x+1)(2x-1)