十字相乘法1).2x2－5x－12(2).3x2－5x－2(3).6x2－13x+5(4).7x2－19x－6(5).12x2－13x+3(6).4x2+24x+27(7).5x²+6x-8(8).2x2+3x+1(9).2y2+y－6(10).6x2－13x+6(11).3a2－7a－6(12).4n2+4n－15(13).6a2+a－35(14)..x2+2x-8=0(15).x2+3x-10=0(16)

Question

十字相乘法
1).2x2－5x－12
(2).3x2－5x－2
(3).6x2－13x+5
(4).7x2－19x－6
(5).12x2－13x+3
(6).4x2+24x+27
(7).5x²+6x-8
(8).2x2+3x+1
(9).2y2+y－6
(10).6x2－13x+6
(11).3a2－7a－6
(12).4n2+4n－15
(13).6a2+a－35
(14)..x2+2x-8 =0
(15).x2+3x-10=0
(16)5x2－8x－13=0
(17)4x2+15x+9=0
(18)15x2+x－2=0
(19)6y2+19y+10=0
(20)20－9y－20y2=0
(21).x2-x-20=0
(22).x2+x-6=0
(31).2x2+5x-3=0
(32).6x2+4x-2=0
(33).x2-2x-3 =0
(34).x2+6x+8 =0
(35).x2-x-12=0
(36).x2-7x+10 =0
(37).6x2+x+2=0
(38).4x2+4x-3=0
(39).x2-6x-7=0
(40).x2+6x-7=0
(41).x2-8x+7=0
(42).x2+8x+7=0
(43).x2-5x+6=0
(44).x2-5x-6=0
(45).x2+5x-6=0
(46).x2+5x+6=0
(47).m²+4m-12=0
(48).6x²-5x-25=0
求答案………………

Answer 1

(1).2x²-5x-12
=(2x+3)(x-4)
(2).3x²-5x-2
=(3x+1)(x-2)
(3).6x²-13x+5
=(2x-1)(3x-5)
(4).7x²-19x-6
=(7x+2)(x-3)
(5).12x²-13x+3
=(3x-1)(4x-3)
(6).4x²+24x+27
=(2x+3)(2x+9)
(7).5x²+6x-8
=(2x-2)(x+4)
(8).2x²+3x+1
=(2x+1)(x+1)
(9).2y²+y-6
=(2y-3)(y+2)
(10).6x²-13x+6
=(3x+2)(2x+3)
(11).3a²-7a-6
=(3a+2)(a-3)
(12).4n²+4n-15
=(2n-3)(2n+5)
(13).6a²+a-35
=(2a+5)(3a-7)
(14).x²+2x-8 =0
(x-2)(x+4)=0
x=2 x=-4
(15).x²+3x-10=0
(x-2)(x+5)=0
x=2 x=-5
(16)5x²-8x-13=0
(5x-13)(x+1)=0
x=13/5 x=-1
(17)4x²+15x+9=0
(4x+3)(x+3)=0
x=3/4 x=-3
(18)15x²+x-2=0
(5x+2)(3x-1)=0
x=2/5 x=1/3
(19)6y²+19y+10=0
(3y+2)(2y+5)=0
y=-2/3 y=-5/2
(20)20-9y-20y²=0
(4-5y)(5+4y)=0
y=5/4 y=4/5
(21).x²-x-20=0
(x-5)(x+4)=0
x=5 x=-4
(22).x²+x-6=0
(x+3)(x-2)=0
x=-3 x=2
(31).2x²+5x-3=0
(x-1)(x+3)=0
x=1 x=3
(32).6x²+4x-2=0
(3x-2)(2x+1)=0
x=2/3 x=-1/3
(33).x²-2x-3 =0
(x+1)(x-3)=0
x=1 x=-3
(34).x²+6x+8 =0
(x+2)(x+4)=0
x=-2 x=-4
(35).x²-x-12=0
(x-4)(x+3)=0
x=4 x=-3
(36).x²-7x+10 =0
(x-2)(x-5)=0
x=2 x=5
(37).6x²+x+2=0
6x²-x+2=0
(3x-2)(2x+1)=0
x=2/3 x=-1
6x²+x-2=0
(3x+2)(2x-1)=0
x=-2/3 x=1
(38).4x²+4x-3=0
(2x+3)(2x-1)=0
x=-3/2 x=1
(39).x²-6x-7=0
(x+1)(x-7)=0
x=-1 x=7
(40).x²+6x-7=0
(x-1)(x+7)=0
x=1 x=-7
(41).x²-8x+7=0
(x-7)(x-1)=0
x=7 x=1
(42).x²+8x+7=0
(x+7)(x+1)=0
x=-7 x=-1
(43).x²-5x+6=0
(x-3)(x-2)=0
x=3 x=2
(44).x²-5x-6=0
(x-6)(x+1)=0
x=6 x=-1
(45).x²+5x-6=0
(x+6)(x-1)=0
x=6 x=1
(46).x²+5x+6=0
(x+3)(x+2)=0
x=-3 x=-2
(47).m²+4m-12=0
(m+6)(m-2)=0
m=-6 m=2
(48).6x²-5x-25=0
(2x-5)(3x+5)=0
x=5/2 x=-5/3