Toán (x+3)^2-(x-2)^2=16 (4x-2)^2-(x+4)(x-4)=0 (5-2x)+4(x^2-2)=10 31/08/2021 By Ayla (x+3)^2-(x-2)^2=16 (4x-2)^2-(x+4)(x-4)=0 (5-2x)+4(x^2-2)=10
* (x+3)² – (x-2)² =16 ⇔ (x+3-x+2)(x+3+x-2) =16 ⇔ 0x+5 =16(vô lý) hay 2x +1 =16 ⇔ 2x =15 ⇔ x=7,5 Vậy S={7,5} * (4x-2)^2-(x+4)(x-4)=0 ⇔ 4x^2-16x+4-(x+4)(x-4)=0 ⇔ (x-4)+4-(x+4)(x-4)=0 ⇔ (4x+4)(x+4)=0 ⇔ 4x+4=0 hay x-4=0 ⇔ 4x=-4 hay x=4 ⇔ x=-1 hay x=4 Vậy S={1;4} * (5-2x)+4(x^2 -2)=10 ⇔ 5-2x+4x^2 -8 =10 ⇔ 4x^2-2x -3=10 ⇔ 2x(2x-1)-13=0 ⇔ (2x-13)(2x-1)=0 ⇔ 2x-13=0 hay 2x -1=0 ⇔ 2x=13 hay 2x=1 ⇔ x=13/2 hay x=1/2 Vậy S={13/2;1/2} Trả lời
Đáp án: Giải thích các bước giải: (x+3)^2 – (x-2)^2 =16 <=> (x+3-x+2)(x+3+x-2) =16 <=>0x+5 =16(vô lý) hay 2x +1 =16 <=> 2x =15 <=>x=7,5 vậy S={7,5} (4x-2)^2-(x+4)(x-4)=0 <=> 4x^2-16x+4-(x+4)(x-4)=0 <=>(x-4)+4-(x+4)(x-4)=0 <=>(4x+4)(x+4)=0 <=>4x+4=0 hay x-4=0 <=>4x=-4 hay x=4 <=>x=-1 hay x=4 vậy S={1;4} (5-2x)+4(x^2 -2)=10 <=>5-2x+4x^2 -8 =10 <=>4x^2-2x -3=10 <=>2x(2x-1)-13=0 <=>(2x-13)(2x-1)=0 <=>2x-13=0 hay 2x -1=0 <=>2x=13 hay 2x=1 <=>x=13/2 hay x=1/2 vậy S={13/2;1/2} Trả lời
* (x+3)² – (x-2)² =16
⇔ (x+3-x+2)(x+3+x-2) =16
⇔ 0x+5 =16(vô lý) hay 2x +1 =16
⇔ 2x =15
⇔ x=7,5
Vậy S={7,5}
* (4x-2)^2-(x+4)(x-4)=0
⇔ 4x^2-16x+4-(x+4)(x-4)=0
⇔ (x-4)+4-(x+4)(x-4)=0
⇔ (4x+4)(x+4)=0
⇔ 4x+4=0 hay x-4=0
⇔ 4x=-4 hay x=4
⇔ x=-1 hay x=4
Vậy S={1;4}
* (5-2x)+4(x^2 -2)=10
⇔ 5-2x+4x^2 -8 =10
⇔ 4x^2-2x -3=10
⇔ 2x(2x-1)-13=0
⇔ (2x-13)(2x-1)=0
⇔ 2x-13=0 hay 2x -1=0
⇔ 2x=13 hay 2x=1
⇔ x=13/2 hay x=1/2
Vậy S={13/2;1/2}
Đáp án:
Giải thích các bước giải:
(x+3)^2 – (x-2)^2 =16
<=> (x+3-x+2)(x+3+x-2) =16
<=>0x+5 =16(vô lý) hay 2x +1 =16
<=> 2x =15
<=>x=7,5
vậy S={7,5}
(4x-2)^2-(x+4)(x-4)=0
<=> 4x^2-16x+4-(x+4)(x-4)=0
<=>(x-4)+4-(x+4)(x-4)=0
<=>(4x+4)(x+4)=0
<=>4x+4=0 hay x-4=0
<=>4x=-4 hay x=4
<=>x=-1 hay x=4
vậy S={1;4}
(5-2x)+4(x^2 -2)=10
<=>5-2x+4x^2 -8 =10
<=>4x^2-2x -3=10
<=>2x(2x-1)-13=0
<=>(2x-13)(2x-1)=0
<=>2x-13=0 hay 2x -1=0
<=>2x=13 hay 2x=1
<=>x=13/2 hay x=1/2
vậy S={13/2;1/2}