Question

Alguien me ayuda pliss 1) 3b-(2b+a)
2) x[2y-2(x+2y)5+y ] e)3b -(-b-2b-4a)-4b
3)9y+[3x-(y+4x)] f)-[6y3 -(y-y2+6y-8y3]
4) x-[9-4(3-x)] g)2(5x-y)-(7x+y)
h)2y-[x-2(x-y)]-[2y-(x+y)]

Answer 1

1)

$3b-\left(2b+a\right)\\-\left(2b+a\right)\\=-\left(2b\right)-\left(a\right)\\=-2b-a\\=3b-2b-a\\=b-a$

2)

$x[2y-2(x+2y)5+y ]\\=x\left(2y+y-10\left(x+2y\right)\right)\\2y-10\left(x+2y\right)+y\\=2y-10x-20y+y\\=-17y-10x\\=x\left(-10x-17y\right)$

3)

$9y+[3x-(y+4x)]\\=9y+3x-\left(y+4x\right)\\-\left(y+4x\right)\\=-\left(y\right)-\left(4x\right)\\=-y-4x\\=9y+3x-y-4x\\=9y-y+3x-4x\\=8y+3x-4x\\=8y-x$

4)

$x-[9-4(3-x)]\\9-4\left(3-x\right)\\=9-12+4x\\=4x-3\\=x-\left(4x-3\right)\\-\left(4x-3\right)\\=-\left(4x\right)-\left(-3\right)\\=-4x+3\\=x-4x+3\\=-3x+3$

e?)

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

f?)

$-\left[6y^3\:-\left(y-y^2+6y-8y^3\right)\right]\\y-y^2+6y-8y^3\\=-8y^3-y^2+y+6y\\=-8y^3-y^2+7y\\=-\left(6y^3-\left(-8y^3-y^2+7y\right)\right)\\6y^3-\left(-8y^3-y^2+7y\right)\\-\left(-8y^3-y^2+7y\right)\\=-\left(-8y^3\right)-\left(-y^2\right)-\left(7y\right)\\=8y^3+y^2-7y\\=6y^3+8y^3+y^2-7y\\=14y^3+y^2-7y\\=-\left(14y^3+y^2-7y\right)\\=-\left(14y^3\right)-\left(y^2\right)-\left(-7y\right)\\=-14y^3-y^2+7y$

g?)

$2\left(5x-y\right)-\left(7x+y\right)\\2\left(5x-y\right)\\=2\cdot \:5x-2y\\=10x-2y\\=10x-2y-\left(7x+y\right)\\-\left(7x+y\right)\\=-\left(7x\right)-\left(y\right)\\=-7x-y\\=10x-2y-7x-y\\=10x-7x-2y-y\\=3x-2y-y\\=3x-3y$

h?)

$2y-[x-2(x-y)]-[2y-(x+y)]\\x-2\left(x-y\right)\\=x-2x+2y\\=-x+2y\\=2y-\left(2y-x\right)-\left(2y-\left(y+x\right)\right)\\2y-\left(x+y\right)\\=2y-x-y\\=y-x\\=2y-\left(2y-x\right)-\left(y-x\right)\\=2y+x-2y-\left(y-x\right)\\=2y+x-2y-y+x\\=-y+2x$