Question

me ajudem pfv no dever ​

Answer 1

Resposta:

a)(3x+5y)(3x-5y)=

9x²-15xy+15xy-25y²=

9x²-25y²=

x=± √25y²/9

x=±(5y/3)

x=+5y/3. ou. x=-5y/3

b)(10+2d)(10-2d)=

100-20d+20d-4d²=

100-4d²=

-4d²=-100

4d²=100

d²=25

d=±√25

d=+5. ou. d= -5

c)(x-1)(x+1)=

x²+x-x-1=

x²=1

x=±√1

x=+1. ou. x=-1

d)(8 +3x)(8-3x)=

64-24x+24x-9x²=

64- 9x²=

-9x²=-64

9x²=64

x²=64/9

x=±√64/9

x=±8/3

x=+8/3 ou x=-8/3