a: Ax⊥ a

Oy⊥a

Do đó: Ax//Oy

b: Ax//Oy

=>\(\hat{xAO}+\hat{AOy}=180^0\) (hai góc trong cùng phía)

=>\(\hat{AOy}=180^0-35^0=145^0\)

c: \(\hat{DOC}+\hat{OCz}=55^0+125^0=180^0\)

mà hai góc này là hai góc ở vị trí trong cùng phía

nên Dy//Bz

mà Dy//Ax

nên Ax//Bz

Ax//Bz

Ax⊥a

Do đó: Bz⊥a

d: OD//Ax

=>\(\hat{AOD}=\hat{OAx}\) (hai góc so le trong)

=>\(\hat{AOD}=35^0\)

OD nằm giữa hai tia OA và OC

=>\(\hat{AOC}=\hat{AOD}+\hat{COD}=35^0+55^0=90^0\)

=>OA⊥ OC

we have:

wow, it's so hard, i am caculating it

X= -20,384

thank you very much

\(7^{2x}+7^{2x+2}=2450\)

\(7^{2x}.1+7^{2x}.7^2=2450\)

\(7^{2x}.\left(1+7^2\right)=2450\)

\(7^{2x}.\left(1+49\right)=2450\)

\(7^{2x}.50=2450\)

\(7^{2x}=2450:50\)

\(7^{2x}=49\)

\(7^{2x}=7^2\)

\(\Rightarrow2x=2\)

\(x=2:2\)

\(x=1\)

Vậy \(x=1\)

\(7^{2x}+7^{2x+2}=2450\)

\(\Leftrightarrow7^{2x}+7^{2x}.7^2=2450\)

\(\Leftrightarrow7^{2x}.\left(1+7^2\right)=2450\)

\(\Leftrightarrow7^{2x}.50=2450\)

\(\Leftrightarrow7^{2x}=2450:50\Leftrightarrow7^{2x}=49\)

\(\Leftrightarrow7^{2x}=7^2\Leftrightarrow2x=2\)

\(\Leftrightarrow x=1\)

giờ bạn ko cho từ sao mik làm dc?

1. collection

2. addicted

1. Lam has a lot af stamps in her collection

2. You must be careful when playing electronic game because the can be addictive

Lần sau viết rõ đề hộ

Bài 3:

* A + B = x² - 2x - y + 3y - 1 - 2x² + 3y² - 5x + y + 3

A + B = −x² + 3y² − 7x + 3y + 2

* A - B = x² - 2x - y + 3y - 1 + 2x² - 3y² + 5x - y - 3

A - B = 3x² − 3y² + 3x + y − 4

Bài 4:

a, M + (5x² - 2xy) = 6x² + 9xy - y²

M = 6x² + 9xy - y² - 5x² + 2xy

M = x² − y² + 11xy

b, (3xy - 4y²) - N = x² - 7xy + 8y²

N = 3xy - 4y² - x² + 7xy - 8y²

N = −x² + 10xy − 12y²

Chúc bn học tốt!

Nguyễn Lê Phước ThịnhMiyuki MisakiHồng PhúcMai.T.LoanHuỳnh Quang SangWhite HoldLinh Nguyễn Trương Huy HoàngHùng NguyễnKakarot Songoku