-8m? -【4m-2m? -(3m-2m? -7)]
=-8m? -(4m-2m? -3m+2m? +7)
=-8m? -4m+2m? +3m-2m? -7
=(-8m? +2m? -2m? )-4m-7
=-8m? -4m-7
3x? -[7x-(4x-3)-2x? ]
=3x? -(7x-4x+3-2x? )
=3x? -7x+4x-3+2x?
=(3x? +2x? )+(-7x+4x)-3
=5x? 3x 3
1/2(a? -b)+ 1/3(a-b? )+ 1/6(a? +b? )
= 1/2a? - 1/2 b+ 1/3a- 1/3b? + 1/6a? + 1/6b?
=( 1/2a? + 1/6a? )- 1/2 b+ 1/3a+(- 1/3b? + 1/6b? )
=2/3a? - 1/2 b+ 1/3a- 1/6b?
5ab? -3【2a? -2(a? b-2ab? )]
=5ab? -3(2a? -2a? b+4ab? )
=5ab? -6a? +6a? b- 12ab?
=(5ab? - 12ab? )-6a? +6a? b
=-7ab? -6a? +6a? b
Simplify first, then evaluate
1/4(-4x? +2x-8)-( 1/2x- 1), where x= 1/2.
=-x? + 1/2x-2- 1/2x+ 1
=-x? - 1
=-( 1/2)? - 1
=- 1/4- 1
=-5/4
(4a? -3a)-(2a? +a- 1)+(2-a? +4a), where a=-2
=4a? -3a-2a? -a+ 1+2-a? +4a
=(4a? -2a? -a? )+(-3a-a+4a)+( 1+2)
=a? +3
=(-2)? +3
=4+3
=7
A-2(2a+b)+3(a-b), where a=-2.
=a-4a-2b+3a-3b
=(a-4a+3a)-(2b+3b)
=-5b
=-5×(-2)
= 10
4x? -(2x? +x- 1)+(2-x? -3x), where x=- 1/2
=4x? -2x? -x+ 1+2-x? -3 times
=(4x? -2x? -x? )-(x+3x)+( 1+2)
=x? -4x+3
=(- 1/2)? -4×(- 1/2)+3
= 1/4+2+3
=2 1/4
5(3a? b-ab? )-(ab? +3a? B) where a = 1/2 and b =- 1.
= 15a? b-5ab? -ab? -3a? b
=( 15a? b-3a? b)-(5ab? +ab? )
= 12a? b-6ab?
= 12×( 1/2)? ×(- 1)-6× 1/2×(- 1)?
= 12× 1/4×(- 1)-6× 1/2× 1
=-3-3
=-6
Is called A=4a? +5b,B=-3a? -2b, find the value of 2A-B, where a =-2 and b = 1.
2A-B
=2(4a? +5b)-(-3a? -2b)
=8a? + 10b+3a? +2b
= 1 1a? + 12b
= 1 1×(-2)? + 12× 1
= 1 1×4+ 12
=56
Known (x+ 1)? +|y- 1|=0, find 2(xy-5xy? )-(3xy? -xy) value.
∫(x+ 1)? +|y- 1|=0
∴x+ 1=0 and y- 1=0.
∴x=- 1,y= 1
2(xy-5xy? )-(3xy? -xy)
=2xy- 10xy? -3xy? +xy
=3xy- 13xy?
=3×(- 1)× 1- 13×(- 1)× 1?
=-3+ 13
= 10
Is called A=x? +2x? y+2y? - 1,B=3+y? +2x? y+2x? If A+B+C=0, find c.
A+B+C=0
C=-(A+B)
C=-(x? +2x? y+2y? - 1+3+y? +2x? y+2x? )
=-x? -2x? y-2y? + 1-3-y? -2x? y-2x?
=-(x? +2x? )-(2x? y+2x? y)-(2y? +y? )+( 1-3)
=-3x? -4x? y-3y? -2