Question

bài 1: tính

a) -6x+3(7+2x)

b)15y-5(6x+3y)

c) x(2x+1)-x²(x+2)+(x³-x+3)

d)4(x-6)-x²(2+3x)+x(5x-4)3x²(x-1)

bài 2: tìm x

a)3x+2(5-x)=0

b)3x²-3x(-2+x)=36

c)5x(12x+7)-3x(20x-5)=-100

Answer 1

Tên chữ Cam là sao

Answer 2

Bài 1:

a) -6x + 3(7 + 2x)

= -6x + 21 + 6x

= (-6x + 6x) + 21

= 21

b) 15y - 5(6x + 3y)

= 15y - 30 - 15y

= (15y - 15y) - 30

= -30

c) x(2x + 1) - x²(x + 2) + (x³ - x + 3)

= 2x² + x - x³ - 2x² + x³ - x + 3

= (2x² - 2x²) + (x - x) + (-x³ + x³) + 3

= 3

d) x(5x - 4)3x²(x - 1) ??? :V

Bài 2:

a) 3x + 2(5 - x) = 0

<=> 3x + 10 - 2x = 0

<=> x + 10 = 0

<=> x = -10

=> x = -10

b) 3x² - 3x(-2 + x) = 36

<=> 3x² + 2x - 3x² = 36

<=> 6x = 36

<=> x = 6

=> x = 5

c) 5x(12x + 7) - 3x(20x - 5) = -100

<=> 60x² + 35x - 60x² + 15x = -100

<=> 50x = -100

<=> x = -2

=> x = -2

Answer 3

tks bn nhiều nha

Answer 4

vif mik vip