有一个两位数,个位数为a,十位数为b,这两位数可表示为(10b+a)
化简:
(1)2x^2+1-3x+7-3x^2+5x
=-x^2+2x+8
(2)2a^-[5a-1/2(a-3)+2a^]
=2a^-5a+1/2a-3/2-2a^
=-9/2a-3/2
先化简,在求值:1/2x-2(x-1/3y^2)+(-3/2x+1/3y^2)
=1/2x-2x+2/3y^2-3/2x+1/3y^2
=-3x+y^2
有一个两位数,个位数为a,十位数为b,这两位数可表示为(10b+a)
化简:
(1)2x^2+1-3x+7-3x^2+5x
=-x^2+2x+8
(2)2a^-[5a-1/2(a-3)+2a^]
=2a^-5a+1/2a-3/2-2a^
=-9/2a-3/2
先化简,在求值:1/2x-2(x-1/3y^2)+(-3/2x+1/3y^2)
=1/2x-2x+2/3y^2-3/2x+1/3y^2
=-3x+y^2