Question

me ajudem pfvv

efetue as multiplicações:

a) 7x.(x-3y)=
b) 3ab.(2a+b)=
c)5xy.(6x+4y-8x+9y)=
d) 12.(x²-7x+3)=
e) 9.(x²+7x-4x)=
f) (x+9) . (x-6) =
g) (7a-b) . (7a+b) =
h) (3x-2) . (x²-5x+6)=
i) (2x+1) . (-6x²-5x+3)= ​

Answer 1

Resposta:

a) 7x.(x-3y)=

${7x}^{2} - 21xy$

b) 3ab.(2a+b)=

${6a}^{2}b + 3 {ab}^{2}$

c)5xy.(6x+4y-8x+9y)=

${30x}^{2}y + 20 {xy}^{2} - 40 {x}^{2}y + 45{xy}^{2} \\ - 10{x}^{2}y + 65x {y}^{2}$

d) 12.(x²-7x+3)=

${12x}^{2} - 84x + 36$

e) 9.(x²+7x-4x)=

${9x}^{2} + 63x - 36x \\ {9x}^{2} + 27$

f) (x+9) . (x-6) =

${x}^{2} - 6x + 9x - 54 \\ {x}^{2} + 3x - 54$

g) (7a-b) . (7a+b) =

${49a}^{2} + 7ab - 7ab - {b}^{2} \\ {49a}^{2} - {b}^{2}$

h) (3x-2) . (x²-5x+6)=

${3x}^{3} - {15x}^{2} + 18x - {2x}^{2} + 10x - 12 \\ {3x} {}^{3} - {17x}^{2} + 28x - 12$

i) (2x+1) . (-6x²-5x+3)=

${ - 12x}^{3} - {10x}^{2} + 6x - {6x}^{2} - 5x + 3 \\ { - 12x}^{3} - {16x}^{2} + x + 3$