Toán (3-×)^4=1 7^2-(15+×)=5×2^2 (×+1)+(×+2)+(×+3)+…..+(×+20) 08/07/2021 By Ariana (3-×)^4=1 7^2-(15+×)=5×2^2 (×+1)+(×+2)+(×+3)+…..+(×+20)
(3-x)^4=1(3-x)^4=1^43-x=1x=3-1=2 7^2-(15+×)=5×2^27^2-(15+x)=2049-(15+x)=2015+x=49-2015+x=29x=29-15=14 Trả lời
(3-x)^4=1⇒3-x = 1⇒x =2 7²-(15+x) =5×2²⇒ 15+x = 49-20=29 ⇒ x=14 (×+1)+(×+2)+(×+3)+…..+(×+20) = 20x + 20×(20+1)/2 =20x +210 Trả lời
(3-x)^4=1
(3-x)^4=1^4
3-x=1
x=3-1=2
7^2-(15+×)=5×2^2
7^2-(15+x)=20
49-(15+x)=20
15+x=49-20
15+x=29
x=29-15=14
(3-x)^4=1⇒3-x = 1⇒x =2
7²-(15+x) =5×2²⇒ 15+x = 49-20=29 ⇒ x=14
(×+1)+(×+2)+(×+3)+…..+(×+20) = 20x + 20×(20+1)/2 =20x +210