Question

(x-1)+(x-4)+...+(x-28)=155

Answer 1

<=> 10x-(1+4+...+28)=155

<=> 10x+145=155

<=> 10x=155-145

<=> 10x=10

<=> x=1

Answer 2

<=>10x -(1+4+...+28) = 155

<=>10x + 145 = 155

<=>10x = 155-145

<=>10x =10

<=>x=1

Answer 3

minh k biet xin loi ban nha!

minh k biet xin loi ban nha!

minh k biet xin loi ban nha!

minh k biet xin loi ban nha!