Question

Bt1 ;Bỏ dấu ngặc rồi thực hiện phép tính

a, -3\(+\)\((\)-4\()\)-\((\)-3\()\)\(+\)\((\)2\(+\)7-10\()\)

b, 3- \((\)-3\(+\)2-7\()\)\(+\)\((\)-4\()\)

c, 7\(+\)\((\)-2-3\(+\)7\()\)-\((\)-2\()\)

d, -\((\)-3\()\)-\((\)-2\(+\)3-8\()\)\(+\)\((\)-6\()\)

Bt2; Rút gọn ;

a, x²-2x-\((\)3x -2x \()\)

b, -\((\)x²\(+\)3x²\()\)-\((\)-5x²\(+\)3x\()\)

c, \((\)x-y \()\)- \((\)x\(+\)3y \(+\)1\()\)

Answer 1

Bài 1 :

a) \(-3+\left(-4\right)-\left(-3\right)+\left(2+7-10\right)=-3-4+3+2+7-10=-5\)

b) \(3-\left(-3+2-7\right)+\left(-4\right)=3+3-2+7-4=7\)

c) \(7+\left(-2-3+7\right)-\left(-2\right)=7-2-3+7+2=17\)

d) \(-\left(-3\right)-\left(-2+3-8\right)+\left(-6\right)=3+2-3+8-6=4\)

Bài 2 :

a) \(x^2-2x-\left(3x-2x\right)=x^2-2x-3x+2x=x^2-3x\)

b) \(-\left(x^2+3x^2\right)-\left(-5x^2+3x\right)=-x^2-3x^2+5x^2-3x=x^2-3x\)

c) \(\left(x-y\right)-\left(x+3y+1\right)=x-y-x-3y-1=-4y-1\)

Answer 2

Bài 1:

a, -3-4) - -327 - 10

= -3 - 4 + 3 + 2 + 7 - 10

= 5 - 10

= -5.

b, 3 - -3 2 - 7-4

= 3 + 3 - 2 + 7 - 4

= 11 - 4

= 7

c, 7 -2 - 3 7--2

= 7 - 2 - 3 + 7 + 2

= 9 + 2

= 11.

d, - -3--23 - 8-6

Answer 3

a) \(- 3 + \left(\right. - 4 \left.\right) - \left(\right. - 3 \left.\right) + \left(\right. 2 + 7 - 10 \left.\right) = - 3 - 4 + 3 + 2 + 7 - 10 = - 5\)

b) \(3 - \left(\right. - 3 + 2 - 7 \left.\right) + \left(\right. - 4 \left.\right) = 3 + 3 - 2 + 7 - 4 = 7\)

c) \(7 + \left(\right. - 2 - 3 + 7 \left.\right) - \left(\right. - 2 \left.\right) = 7 - 2 - 3 + 7 + 2 = 17\)

d) \(- \left(\right. - 3 \left.\right) - \left(\right. - 2 + 3 - 8 \left.\right) + \left(\right. - 6 \left.\right) = 3 + 2 - 3 + 8 - 6 = 4\)

Bài 2 :

a) \(x^{2} - 2 x - \left(\right. 3 x - 2 x \left.\right) = x^{2} - 2 x - 3 x + 2 x = x^{2} - 3 x\)

b) \(- \left(\right. x^{2} + 3 x^{2} \left.\right) - \left(\right. - 5 x^{2} + 3 x \left.\right) = - x^{2} - 3 x^{2} + 5 x^{2} - 3 x = x^{2} - 3 x\)

c) \(\left(\right. x - y \left.\right) - \left(\right. x + 3 y + 1 \left.\right) = x - y - x - 3 y - 1 = - 4 y - 1\)