System of equation:
Let $x_1,x_2,\ldots,x_7$ be real numbers such that
$$
\begin{align*}
x_1+4x_2+9x_3+16x_4+25x_5+36x_6+49x_7&=1\
4x_1+9x_2+16x_3+25x_4+36x_5+49x_6+64x_7&=12\
9x_1+16x_2+25x_3+36x_4+49x_5+64x_6+81x_7&=123
\end{align*}
$$Find $16x_1+25x_2+36x_3+49x_4+64x_5+81x_6+100x_7$

Question

angela210793 · Answer

O.o

anonymous · Answer

i think its 1234 why look to the number of $$x_ 1$$ 4 9 16 now $$x_2$$ 4 9 16 25 and so the answers was 1 and 12 and 123 there is a Relationship between the numbers what do you study ? is it Series ?

watchmath · Answer

No, that is not right! :D

anonymous · Answer

what do you study matrix or Series or solve equation ? that will help to find the method of solve but the number is very strange 1 ,4(3+1),9(4+5),16(9+7) ......

watchmath · Answer

This is not related to any course :). It is just an elementary problem that needs some creativity to solve it.